HDV 78-03 Technical Report May 1978 Truck Driving Pattern and Use Survey Phase II Final Report Part II Los Angeles by Leroy Higdon May,197*f NOTICE Technical Reports do not necessarily represent final EPA decisions or positions. They are intended to present technical analysis of issues using data which are currently available. The purpose in the release of such reports is to facilitate the exchange of technical information and to inform the public of technical developments which may form the basis for a final EPA decision, position or regulatory action. Standards Development and Support Branch Emission Control Technology Division Office of Mobile Source Air Pollution Control Office of Air and Waste Management U.S. Environmental Protection Agency ------- Forward This report presents the data collection procedures used in Phase II Part II of the CAPE-21, Truck Driving Pattern and Use Survey. It covers only the data collection in Los Angeles, and describes collection processes, equipment, personnel, sample plans and resultant data base. No attempts are made to show conclusions as to the validity of the data since this topic will be covered in a separate report to be released at a later date. ------- Table of Contents Page I. Introduction 1 II. Program Structure 4 III. Data Collection 26 IV. Summary 41 ------- List of Illustrations Page Figure 1 Sample Plan for Los Angeles 6 Figure 2 Georgraphic Sample Plan for Los Angeles ... 7 Figure 3 Registration Listings 9 Figure 4 Agreement 13 Figure 5 Block Diagram Data Acquisition System .... 18 Figure 6 Metro Data Acquisition System 19 Figure 7 Cassette Data Format 31 Figure 8 "Z" Test Output 32 ------- List of Tables Table 1 Truck Acquisition Response Summary . . . Table 2 Channel Assignment Table 3 Test Equipment Table 4 L.A. Trucks by Manufacturers Table 5 Survey Data Base Page 12 20 23 27 36 ------- -1- I. Introduction A. Background Phase II Part II of the CAPE-21, Truck Driving Pattern and Use Survey Is the continuation of: a two city survey consisting of New York and Los Angeles. This report deals only with Part II of the CAPE-21 program, and covers the Los Angeles survey. The New York portion of the CAPE-21 program was conducted by Wilbur Smith and Associates and is covered in a final report under the heading Phase II Part 1, Truck Driving Pattern and Use Survey. The selection of the two cities which make up the study was made •jointly by a panel of representatives from the U.S. Environmental Protection Agency (EPA) and the Coordinating Research Council (CRC). It was based on the need for in-use heavy-duty truck data which, when analyzed, would indicate typical truck operation in urban areas of the United States. To test a statistically acceptable number of vehicles in each urban area in the United States for the purpose of determining how heavy-duty vehicles are operated in normal service in each case, would have involved the expenditure of vast amounts of manpower and finances and would have taken a significant amount of time to complete. To overcome these restrictions the CAPE-21 panel decided to select two cities which, when combined statistically, represented the extremes in driving conditions under which heavy-duty vehicles must operate. The city of New York was chosen as representative of one extreme, because it is an old city having a dense population in a relatively small area, with narrow streets, limited numbers of expressways, and numerous restrictions to automotive traffic movement in the form of traffic control devices (stop lights and signs). The choice of Los Angeles for the second city in the survey was made because it represents just the opposite in extremes from New York. The rationale for the selection of the two cities has been shown to be correct in an earlier study conducted by Wilbur Smith and Associates of Columbia, South Carolina. "' The program objective was to collect engine and vehicle operational data on a number of in-use heavy-duty trucks and buses, which would, when analyzed, describe the way these vehicles are operated in regular use by their owners. The data collected during the survey were intended for use in the development of representative driving cycles for use. in the testing of heavy-duty trucks and/or truck engines for compliance with emission standards for the control of air pollution. From the standpoint of emission testing for air quality control, the optimum in any test cycle is reached when a single representative cycle can be used which is representative of the way vehicles 'are operated in the control ------- -2- area of interest as a whole. To acheive this, the data base used in the development of such a cycle must be representative of types of vehicles predominantly used in areas which, when combined, represent the mean in operational characteristics within the control area. The CAPE-21 program, through careful design of its sample plan, is a comprehensive study which will supply a data base that is statistic- ally representative of heavy-duty truck operations in two localities. When combined, this data base should reasonably represent the mean in truck operation within the continental United States (the control area of interest). Phase II of the CAPE-21 program was conducted at a cost of just over $250,000.00, excluding salaries, and an expenditure in manpower of approximately 19,000 manhours. The Los Angeles survey was started in January, 1975, and ran to May 1975. This report deals only with the statistical sample plan, data collection operations, and instrumentation used in the Los Angeles portion of the survey. Analysis of the data is the subject of a separate project and will be reported on under separate cover. B. Conclusion In-use data collection of the type sought in the CAPE-21 Truck Driving Pattern and Use Survey is, in the authors opinion, bordering on the upper extremes of state of the art for in-use motor vehicle data collection. This condition is aggravated by the fact that the owners involved in studies of this type are commercial operators depending on these vehicles for profit revenue, a condition which strongly influences every facet of the study. Participation by owners in in-use programs of this type is greatly dependent on their awareness of problems of air pollution, and the need for its control. In addition to this, the will- ingness to participate extends only to the point where economics are not a factor. During the performance of the Los Angeles portion of the CAPE-21 study, every effort was made to inform the participants of the EPA's need for conducting the study. Wherever possible the cost to owners caused by the use of his vehicle in the survey was absorbed by EPA. The results of this effort was an exceptional response on behalf of the participants to aid in the success of the study. With the completion of the Los Angeles Study, EPA has established the formation of the most in-depth data base of in-use heavy-duty truck operation ever assembled. The data describe, in explicit detail, the operational characteristics of heavy-duty vehicles in actual use by the operators. It is free from the outside influences or restrictions in- herent in studies of this type when conducted entirely by skilled test drivers and technicians. It depicts the movement of heavy-duty vehicles in normal traffic over unpredicted routes in terms of road speed, and the engine operational characteristics (RPM and power) from which this ------- -3- road speed is derived. There can be little question as to the representativeness of the data collected in the Los Angeles survey, in that every precaution was taken to insure that the operators were not influenced in any way by the survey team or the on board equipment, in the performance of their normal duties. The data base resulting from the CAPE-21 study is applicable to a wide variety of investigative endeavors and should prove to be unparal- leled in its usefulness for some time to come. It is not, however, unlimited in its ability to answer or satisfy all possible questions concerning the movement of heavy-duty vehicle operation in urban areas of the United States, and when used should be considered with the same degree of technical understanding afforded any other data base for its original intent. ------- -4- II. Program Structure A. Purpose The CAPE-21 program was designed, and conducted to provide a data base from which heavy-duty engine and chassis emission test cycles might be developed which are representative of operation in the real world. The data then have the ability to represent the mean operational charac- teristics in the sample area from which it came. B. Sample Plan When planning to undertake a program like CAPE-21, one must first decide on the area to be sampled and having done so identify the para- meters to be sampled within the area. If the data to be collected are to be used to represent the mean of the measured parameters within the area, or if the area under consideration is assumed to be represented by the data as being the norm or average characteristics as a function of the area, then some method must be devised to measure the extremes which can then be used to predict the means. When considering the extremes of the sample area, it is necessary to consider the kind of data needed and identify those parameters, within the sample area of interest, which most greatly influence these parameters. The sample area, in this case, is the United States, and the mean can be derived if the extremes of the area are known. The total area of the selected extremes can further be reduced in size when consideration is given to the fact that, the EPA is primarily concerned with urban areas in its efforts to control air quality. The test means (sample size) can now be confined to vehicle operation within these extremes. Because the study is concerned with traffic flow within the selected portions of the extremes, the controlling factors in the types of data that will result from the testing of vehicles within the recognized confines of the sample area are directly relatable to the means in the types of restrictions to traffic flow. With the above considerations in mind, the city of New York was considered as meeting one extreme because it is an old city having narrow roadways, few limited access roads (freeways), a traffic control system which consists of stop lights and stop signs requiring frequent stop and start type operation, and external interference to traffic flow, in the form of pedestrian crossing, in high volume at peak traffic hours. Additionally, New York's major industries have been distinctly located in specific sections of a city of relatively small area compared to Los Angeles, the second city used in the survey. It was felt that Los Angeles represents the opposite in every category mentioned above. These two cities then were considered the area extremes for the CAPE-21 Truck Driving Pattern and Use Survey. To satisfy the requirement for data which can be used for engine and/or chassis cycle development, the parameters of major concern are 1) ------- —5— engine RPM, 2) engine horsepower and, 3) vehicle road speed. Sample area parameters which most greatly effect these operational parameters are, ]) topography, 2) degree of congestion which attributes restric- tions to traffic flow, 3) traffic control systems, and 4) uncontrollable and periodic interference to traffic flow (i.e., pedestrian movement). In order to select the survey sample configuration, a Heavy-Duty Vehicle Driving Pattern and Use Survey was conducted by Wilbur Smith and Associates (WSA) ' under joint contract from EPA and CRC (Coordinating Research Council) .. This survey (referred to as CAPE-21 Phase 1 Parts 1 and 2 for New York and Los Angeles respectively) was conducted in order to acquire information pertaining to the composition, function, and travel behavior of urban truck travel in the two cities. From Part 2 of these data, a sample plan, which for economical reasons was restricted to fifty (50) vehicles, was designed by WSA which, statistically, was representative of the truck population in the Los Angeles Basin. (See figure 1.) After reviewing the Phase I Part 2 data and the resultant sample plan submitted by WSA, several changes were made to better facilitate the engineering and economical considerations of the data collection program. The final sample plan used in the. Phase II Part 2 Los Angeles survey (see figure 2) called for a total of fifty (50) vehicles to be tested from five (5) geographical areas in the greater Los Angeles basin. Each vehicle was required to have a gross vehicle weight (GVW) of not less than ten (10) thousand pounds and would be tested for from two (2) to five (5) days of normal in-service operation. A day of operation was defined as any twenty-four (24)"hour calendar period during which a vehicle Left its normal storage location, for one hour or more duration, to perform a task or number of tasks, the length of which was immaterial. In addition to the fifty (50) vehicles originally scheduled to be tested in the CAPE-21 program, five city busses were added to the study in both New York and Los Angeles. These vehicles were to be. tested both as inter-city as well as intra-city vehicles and were acquired from the major transportation agencies in each location. As an afterthought, and because the opportunity presented itself favorably. Two trucks, one two axle tractor trailer, gas, and one two axle single unit, gas, were instrumented and driven over the road be- tween Los Angeles and San Francisco, California, and between Los Angeles, California and Ann Arbor, Michigan. Similarly, a Trailways over-the- road bus was tested between Los Angeles, California and Denver, Colorado. Vehicles were divided into four (4) groups by axle configuration. Two axle single unit (2A), three axle single unit (3A), two axle tractor trailer (2TT) and three axle tractor trailer (3TT), busses were consid- ered as a separate category. The sample was further divided into two fuel classes, gasoline and diesel. In order to qualify as being repre- sentative of operation in a given geographical area, a vehicle had to ------- FIGURE 1 SAMPLE PLAN FOR LOS ANGELES Strata 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 6-10 6-10 10-15 10-15 15-20 15-20 6-10 6-10 10-15 10-15 15-20 15-20 20-25 20-25 6-10 6-10 10-15 10-15 15-20 15-20 20-25 20-25 25-30 25-30 30-35 30-35 +35 ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, ,000, 2 2 2 2 2 2 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 4 Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Axle, Number of Trucks RC BE RC BE RC BE RC BE RC BE RC BE RC BE RC BE RC BE RC BE RC BE RC BE RC BE BE TOTAL 10 8 2 1 0 0 0 1 1 3 1 1 0 0 0 0 0 0 1 1 2 4 1 8 1 3 1 50 Number of Days 4 - 4 4 4 - - - 4 5 5 3 4 - - - - - - 4 3 3 4 2 2 2 2 2 Truck Days of Data 40 32 8 4 - - - 4 5 15 3 4 - - - - - - 4 3 6 16 2 16 2 6 2 172 RC - Regular Commercial; BE - California Board of Equalization Column 2 indicates the number of days truck is to be tested. ------- FIGURE 2 GEOGRAPHIC SAMPLING PLAT; FOR LOS ANGELES COUNTY (CAPE-21) Truck Type 2A 3A 2TT 3TT All Areas Gas Diesel No. No. No. No. No. No. No. No. Trucks Truck Days Trucks Truck Days Trucks Truck Days Trucks Trucks Days 20 80 3 12 5 16 2 8 3 8 4 20 5 10 8 18 Los Angeles Gas Diesel 8 32 1 4 2 4 1 4 1 4 1 5 2 4 3 6 Inglewood Gas Diesel 3 12 1 4 1 4 0 0 0 0 0 0 1 2 1 3 Van Nuys/ Pasadena Gas Diesel 3 12 0 0 1 4 0 0 0 0 1 5 0 0 1 3 Whittier/ Long Beach Gas Diesel 4 16 0 0 1 4 1 4 1 2 1 5 2 4 2 4 Alhambra Gas Diesel 2 8 1 4 0 0 0 0 1 2 1 5 0 0 1 2 Totals 23 88 7 32 10 26 10 26 oo 2TT 3TT ------- -8- have originated its daily operation in that area. C. Vehicle Acquisition Olson Laboratories Inc. (OLI) of Anaheim, California, under contract to EPA to support the survey team, was supplied with listings of commer- cially registered vehicles of the truck classes sought, by the Department of Motor Vehicles for the state of California. The listing, a copy of which is seen in figure 3, consisted of information regarding type of truck, number of axles, weight, fuel type, and registered owner's name and address. Using the listing OLI personnel contacted 480 owners by phone in an attempt to locate the required vehicle in the required operating locale. Two hundred twelve (212) owners meeting both truck type and location requirements were contacted, of which sixty-two (62) agreed to participate in the study. The difficulties experienced in finding willing participants lie primarily in the information source employed. As can be seen in figure 3, only the registered name and address of owners are listed, this information does not indicate if the vehicle is based at that location. During the survey it was found that, in fact, some vehicles were not even based in the state of California. Vehicles were finally obtained by starting with registered owners and tracing the truck whereabouts by phone until a definite answer could be obtained from the operator as to his willingness and ability to partici- pate. In addition to difficulties experienced in locating the required vehicles, it was found that owners were reluctant to participate in the program when it was learned that the study was being conducted by a government agency. This problem stemmed from the fact that not only was the truck to be instrumented, but that an on-board observer working for the government would ride with the equipment. The thought was expressed by owners that more was being monitored than vehicle operation. To overcome this distrust, personal visits were made to prospective parti- cipants to explain the intent of the survey and answer any questions, this reduced declines to acceptable levels in California. Table 1 shows the statistics for truck acquisition, and the resultant sample population. Once the required vehicle was found the owner was required to sign a written agreement authorizing the installation of the instrumentation, and describing the legal obligations and limitations. The vehicle was then delivered to one of two dynamometer facilities for installation and calibration. D. Vehicle Instrumentation Installation Scheduling Once a participation agreement was secured, a vehicle was entered into the scheduling process. This process consisted of obtaining a signed agreement with the owner of the vehicle (figure 4), inspection of the vehicle prior to instrumentation installation, and scheduling of the vehicle for installation. ------- FIGURE 3 DEPARTMENT OF MOTOR VEHICLES, STATE OF CALIFORNIA REGISTRATION LISTINGS Axle Group 3 3 3 3 3 3 3 3 3 Weight Group 15-20K 15-20K 15-20K 15-20K 15-20K 15-20K 15-20K 15-20K 15-20K Year 65 73 69 71 69 69 66 64 67 Model PTB KEN MCK WST KEN KEN WHI KEN PTB Truck Type TAN TRA TRA FLA TRA TAN TRA TRA TRA Cab Loc. U U U U U U U U U Wheels Fuel Tot. D 9 D 9 D 9 D 9 D 9 D 9 D 9 D 9 D 9 Dr. 9 9 9 9 9 9 9 9 9 State Weight 060 054 057 060 050 060 050 050 050 Name Douglas Oil Co. Seven Flags Co-Op Dresser In- dustries Inc. Sun Lumber Co. Selectruk, Inc. Southern Tank Lines Mr . Donald W. Smith Davidson C. L. Truck- ing, Inc. Mr. Clifford J. Turner Address 1 816 West 5th St. 12420 Bloom- field Av. 10960 Wil- shire Bl. 3435 Wil- shire Bl. 5030 Gif- ford Av. 16613 Minn- esota Av. 12004 S. Louis Av. 420 Camino De Encnt. 10919 S. Van Ness Av. Address 2 Los Angeles, CA 90017 Sante Fe Springs , CA 90670 Los Angeles, CA 90024 Los Angeles, CA 90010 Los Angeles, CA 90058 Paramount , CA 90723 Whittier, CA 90605 Redondo Beach, CA 90277 Inglewood, CA 90303 ------- FIGURE 3—Continued Axle Weight Truck Cab Wheels State Group Group Year Model Type LOG. Fuel Tot. Dr^ Weight Name Address 1 Address 2 3 15-20K 65 PTB DUM U D 9 9 057 Mr. David C. 10342 Rio El Monte, Delacruz Hondo Pkwy. CA 91733 3 15-20K 64 KEN TRA U D 9 9 050 Wilennis, 1136 E. Los Angeles, Inc. 58th Dr. CA 90001 3 15-20K 72 KEN TRA U D 9 9 054 Mr. Richard 3308 N. Burbank, F. Millar Lamer St. CA 91504 3 15-20K 67 PTB TRA U D 9 9 054 Mr. Walter 15002 Kings- San Fernan- C. Welty bury St. do, CA 91340 3 15-20K 64 KEN TRA U D 9 9 054 Mr. Anthony 247 N. San- La Puente, G. Resales dalwood Av. CA 91744 3 15-20K 65 PTB TAN U D 9 9 057 Colbro Corp. 14011 S. Los Angeles, Central Av. CA 90059 3 15-20K 68 KEN TRA U D 9 9 050 Berkeley In- 355 S. Los Angeles, vestments, Flower St. CA 90017 Ltd. 3 15-20K 67 KEN TRA U D 9 9 054 Mr. James 2356 S. Los Angeles, B. Hicks Sepulveda CA 90064 Bl. 3 15-20K 67 WHI TRA U D 9 9 050 Mr. Essix 2820 Cen- Lynwood, Harris tury Bl. CA 90262 3 15-20K 68 PTB TRA U D 9 9 050 Gray Trk. 4280 Ban- Los Angeles, Co. dini Bl. CA 90023 ------- FIGURE 3—Continued Axle Weight Truck Cab Wheels State Group Group Year Model Type LOG. Fuel Tot. Dr. Weight Name Address 1 Address 2 3 15-20K 67 KEN TRA U D 3 15-20K 69 FOR TMX U D 3 15-20K 66 AUT TRA N D 3 15-20K 71 KEN TRA U D 3 15-20K 72 KEN TRA U D 3 15-20K 69 WHI DIM U D 3 15-20K 72 WFT TRA C D 9 9 054 9 9 050 9 9 050 9 9 050 9 9 050 9 9 060 9 9 050 Ball Son Transfer Greenes Ready Mixe'd Griffith Co. J. V. Trucking Jersey Maid Milk Prod. Alusa West- ern , In c . Ameron 1136 Clint- wood Av. 19030 S. Normandie Av. 3650 Cherry Av. 510 W. 6th St. 1040 W. Slauson Av. Box 575 400 S. Atlantic Bl. La Puente, CA 91744 Torrance, CA 90502 Long Beach, CA 90807 Los Angeles CA 90014 Los Angeles CA 90044 Azusa, CA 91702 Monterey Park, CA 91754 15-20K 70 WFT TRA C D 9 9 054 Atlantic 515 S. Los Angeles, Richfield Flower St. CA 90017 Co. ------- -12- TABLE 1 TRUCK ACQUISITION RESPONSE SUMMARY No longer own or not in service . 20 Lease truck-owner not willing 12 No room in cab for observer 21 Too busy (too much trouble) 40 Don't want to be bothered 10 Unqualified refusal 9 Other reasons for refusal 3 Security problems 2 No longer business 4 .Several contacts and call backs with no response or decision 12 Not listed in telephone directory or unlisted number 2 Legal problems 5 Insurance problems 7 Union problems 3 TOTAL 150 Total sample available for testing out of 212 possible—62. ------- -13- FIGURE 4 AGREEMENT This agreement is between whose address is and who is the owner or operator of a motor vehicle bearing the license and hereafter referred to as owner, and Olson Laboratories Incorporated, a corporation in the State of Minnesota, whose home of- fice is 421 East Cerritos Avenue, Anaheim, California, and hereafter referred to as the consultant. The purpose of the agreement between the two parties is to describe the participation of the owner in certain experiments to be conducted by the consultant under a study sponsored by the U.S. Environmental Pro- tection Agency. The experiment involves the instrumentation of the owner's vehicle described above by the Environmental Protection Agency and the placing of a consultant's observer on the vehicle as a passenger during normal operations of the owner's vehicles, during days be- tween and , hereinafter referred to as the experi- ment period. The owner agrees to deliver at his expense and using his driver, the said vehicle to the consultant's facility at , on between the hours of and for the purpose of installation and calibration of equipment to automatically monitor that vehicle's engine speed, vehicle speed, engine load factor and other vehicle parameters by equipment and means provided by the Environmental Protection Agency and the consultant. The Environmental Protection Agency and the consultant agree to perform this installation in a manner and location so as to not inter- fere with the normal function or operation of the said vehicle. The consultant will provide an observer during the experiment pe- riod to ride on said vehicle during its normal operation and to make such observations and enter into the consultant's log such data that might be observed by him during the experiment period. The consultant agrees that the observer will not engage in any other function than his observation activity and the owner will not require the observer to en- gage in any such activity other than that described. The consultant will be responsible for all damages and liabilities resulting from the installation, data recording and removal of equip- ment on the owner's vehicle, and all actions of the consultant's employ- ees, the consultant's subcontractor's employees, and other agents acting for the consultant. The consultant will hold the owner free from per- sonal and property damages and other liabilities related to said equip- ment and the actions of the consultant's employees. ------- -14- FIGURE 't—Continued The owner will hold the consultant free from any liabilities or re- sponsibilities for any act or damages caused by or to the owner's vehi- cle and employees, including delays, accidents, or other incidences re- lated to all normal functions, operations and use of the said vehicle. The rights in the data collected shall be vested in the consu]tant and assignees for the purposes of the study, except however, the con- sultant agrees not to identify or otherwise relate the owner or his em- ployees to the data so collected without specific written permission of the owner or the employee so involved. To compensate the owner for all expenses involved in the participa- tion in the experiment and all conditions related thereto, the consult- ant agrees to pay to the owner the sum of within 30 days of the conclusion of said experiment. This agreement is accepted by both parties, this day , 19 , and is executed in , in the county of and the State of Witnesseth: For the Owner For the Consultant OLSON LABORATORIES, INC. By By Title Title ------- -15- Vehicle inspection prior to installation, although planned to take place two days before installation, was difficult to achieve in most cases because it involved holding a vehicle out of service for one or more hours while the inspection was performed. Owners who chose to participate in the program did so somewhat reluctantly when told that the vehicle would be out of service for from three to five hours on the day of instrumentation installation. When asked to hold a vehicle out of service for an additional period of time for an inspection, refusals were quite common. In addition to owner reluctance, vehicle pre-inspec- tion was discontinued in Los Angeles because in those instances where it was performed and defects found that would influence the test if not repaired, owners were not agreeable to making such repairs unless it effected the normal work the vehicle was to do. For example, worn tires that might blow during dyno testing but were considered acceptable for normal driving would not be replaced, broken speedometer cables or related parts were of no importance to owners from an operation stand- point, but were vital to the survey needs. Whenever possible, items in need of repair or replacement were put in operating condition by the survey team at their expense, in order to prevent losing the use of the vehicle. Obviously, this did not apply to high cost items such as tires. When repairs were considered unreasonable and the owner could not be persuaded to perform them, the vehicle was rejected and a replace- ment vehicle located. Calibration and installation of instrumentation was performed at two (2) locations in Los Angeles. Each installation was equipped with a Clayton tandom water brake chassis dynamometer. These dynamometers were owned and operated by the 1) State of California Vehicle Mainte- nance Department of the California Department of Transporation, located in Hollywood, California, and 2) the California Air Resources Board at El Monte, California. Five (5) sets of instruments were used in the conduction of the survey. These instruments were mounted in the vehicle in a location which allowed easy access by the on-board observer without interfering with the driver. Vehicle scheduling depended totally on 1) an instrument being available for use and 2) the ability of an owner to deliver the promised vehicle. Initial operation program plans called for the instrumenting of four vehicles per day (assuming instrumentation availability) during normal working hours. In practice, however, only two vehicles proved to be the practical extent to which instrumentation installation could be expanded. This means that on the average four trucks could be tested per week, instead of eight, the number originally targeted. Loss of a given day's operation for a vehicle because of instrument failure, or vehicle breakdown required the slippage of all subsequent vehicles. Most owners required a minimum of one day advance notice for vehicle insturmentation. This was necessary to allow for scheduling of a replacement vehicle to cover scheduled routes or tasks for that com- pany's operation during the four to five hours required for instrument installation. In most cases, if slippage occurred due to a loss of data ------- -16- it was not known until late in the day. This meant owners scheduled for installation the next day were unavailable and cancellation of that vehicle meant a loss of as many days as needed for rescheduling or replacement. Close control of instrument repair, and quick response to in-operation failure reduced loss time substantially in Los Angeles, however, a total of fourteen (14) days were lost to this problem. E- Vehicle! Calibration As will be discussed in more detail later in this report, the primary data parameters collected in the CAPE-2.1 survey were: \ 1. Road speed, 2. Load factor, and 3. Engine RPM. Of the three parameters, load factor represented the most difficult parameter to measure. The reasons for this stem from the fact that when testing heavy-duty engines for compliance with emission control regula- tions, an engine dynamometer is used to exercise the engine through the test procedure. Power measurements are then engine shaft power. For economical as well as practical reasons engine shaft power mea- surements were not possible while the vehicle was being operated in normal use as in the Los Angeles or CAPE-21 study. An alternative solu- tion then would be to measure some other parameter more easily accessible and relative to engine shaft horsepower. The relationship between fuel flow and power in diesel engines as well as manifold pressure in gasoline engines is well known in the automotive industry and was therefore used in the CAPE-21 study. This alone did not completely solve the unique problem created by the CAPE-21 program structure because the program did not allow for removal of the engine from the vehicle for calibration of the load factor measurement with shaft horsepower. It was decided that calibration of load factor measurements could be accomplished by relating load factor measurements to the vehicles rear wheel horsepower and later adding the characteristic losses in transmissions, and differentials (i.e., drive train) to arrive at shaft horsepower. This assumption holds true when horsepower is expressed in terms of percent of maximum wheel horsepower and must equal 100% or maximum shaft horsepower, and can be expanded to intermediate power settings if one assumes the same relationship at all intermediate powers, i.e., drive train losses are linear with RPM. Later in other reports dealing with the CAPE-21 data analysis , this assumption will be shown to be false, but for discussion purposes, it will be maintained here. F. Data Acquisition Package The data acquisition system used included sensors to measure engine ------- -17- RPM; vehicle speed; engine load factor; engine.temperature; and throttle valve position; sensor signal conditioning electronics; and a digital data logger with integral clock and magnetic tape recorder. Manually operated switches were included to enable recording of road type and traffic conditions for subsequent correlation with the sensor data. The above signals, along with time of day from the data logger clock, were sampled and recorded at the rate of one data set every 0.863 seconds. A system block diagram is shown in figure 5. 1. Data Logger The central component of the data acquisition system is the Metra- data Model DL620B Data Logger, figure 6. This unit accepted eight differential data inputs of 0 to + 1 Vdc, scanned them sequentially, and converted the analog signal to a 16-bit (3 digits plus sign) digital signal. These eight channels, plus two channels of time, pre-parity, and parity bits, were assembled into a scan which was recorded at a rate of 1.2 scans per second. This digital data was recorded on a 4-track, 1/4-inch tape in a BCD complement format at a density of 150 bits per inch. The tape was loaded in a 1200-foot endless loop cassette, which provided 12 hours of continuous recording. Front panel controls on the Data Logger included the POWER switch, Analog Display with CHANNEL SELECT switch, and TIME SET controls. Time was displayed on Channels 1 and 2 in the same manner as other channels. The channel format for all tests has been listed in Table 2. 2. Signal Conditioning Module Signals from the transducers were fed into the Signal Conditioning Module. The Signal Conditioning Module provided interfacing and conver- sion between transducer and data logger. 3. Power Supply A separate 12 V battery powered the data acquistion system, and was controlled by a front panel switch. An indicator switch showed system power status. 4. Road Type and Traffic Conditions Manual inputs for road type (freeway arterial and local) and traf- fic conditions (heavy, medium, and light) were programmed by two sets of switches on the front panel of the signal conditioner. These switches were operated by the on-board observers, and were interlocked to prevent selection of more than one condition for either of the two parameters. Selection of a given road type or traffic condition switch applied one of three voltages to the recorder coded as follows: ------- -18- VEHICLE SPEED FILTER RPM LOAD FACTOR IDLE STOP SWITCH ENGINE TEMP. F/V CONVERTER L ATTEN- UATOR F/V CONVERTOR ATTEN- UATOR ± 15V CONVERTER WYLE MANUAL SWITCHES 5 VOLT REG SIGNAL CONDITIONER 12V BATTERY "I VEHICLE BATTERY DL-620-B DATA LOGGER FAN FIGURE 5 Block Diagram - Data Acquisition System ------- -19- 1. System Power 2. Manual Input - Traffic 3. Manual Input - Road Type 4. Power Indicator 5. 5 Amp. Power Fuse 6. RPM Sensitivity Adjust 7. Load Factor Sensitivity 8. Vehicle Speed Adjust 9. Inverter Power Fuse 10. Illuminated Power Switch 11. Illuminated Mode Switch - Standby/Record 12. Record Rate Switch (locked) 13. Thumbswitches to set Real Time 14. Time Reset Button - Starts Real Time 15. Channel Select - Displays in Item 16 16. Channel Data Display 3-Digit + Sign 17. Polarity Display - Lights on (-) 18. Cassette Release Lever 19. Mode Test Switch FIGURE 6 ------- -20- TABLE 2 CHANNEL ASSIGNMENTS DURING CALIBRATION Channel No. Measurement 1 Truck No. and Time (hours tens) 2 Time (hours units and minutes) 3 Engine RPM 4 Load Factor 5 Vehicle Speed 6 Road Type 7 Traffic Conditions 8 Slow Idle Position 9 Engine Temperature 10 Channel 5 Techgenerator Verifi- cation ------- -21- Selected Coded Input Switch Condition Voltage Level Road type Freeway -860 + 30 mv " Arterial 0 + 30 mv " Local +860 + 30 mv Traffic Condition Light -860 + 30 mv " Medium 0 + 30 mv " Heavy +860 + 30 mv 5. Vehicle Speed The input signal for vehicle speed was an AC signal from a Shaft Encoder. The frequency of the encoder was converted to a voltage level which was proportional to vehicle speed. A recurrent problem with vehicle speed shaft encoders producing an output when the vehicle was not in motion was experienced during field operations. The problem was solved by installing an additional speed transducer, of the tachometer-generator type, in the speedometer cable drive. The output from this transducer was connected to Channel 10 on the data logger to indicate when the vehicle was stopped. The tachometer generator output was reliably zero when the vehicle was stopped. The presence of a signal from this unit was used to confirm the validity of the Channel 5 readings. 6. Engine RPM The engine RPM input was derived from the ignition coil or a shaft encoder and was a series of pulses with a DC level of 0.5 to 6 volts and a frequency proportional to RPM. The resultant pulse train was converted fo a DC signal proportional to input frequency by a frequency to voltage (F/V) converter and adjusted to a scale factor approximately 0.1 v/1000 RPM. An alternate RPM input to the Signal Conditioner was provided for on vehicles with mechanical tachometers. For engines which had a mechan- ical tachometer drive, engine RPM was measured by use of an optical shaft encoder. 7. Load Factor Load factor signal sources were pressure transducers for gasoline and Cummins Diesel engines, and a displacement transducer for Detroit Diesel engines. a. Gasoline Engines - The engine load factor for gas engines was obtained using a Bourns Model 556 Pressure Transducer with a range of 0- 15 psig to measure intake manifold pressure. The unit was mounted on the inside of the signal conditioning box. The transducer connected to the intake manifold with a section of 1/4-inch automotive vacuum tubing approximately ten feet long. A snubber valve was placed in the vacuum ------- -22- line to protect the transducer from damage. b. Detroit Diesel Engines - The engine load factor for Detroit Diesel engines was obtained by measuring the angular displacement of the rack using a Research Inc. Model 4045-3 linear displacement transducer. The "rack" is a mechanical device which alters the settings of the engines fuel injectors thereby changing the fuel charge to the cylinders which in turn control the available engine power. c. Cummins Diesel Engines - The load factor transducer for Cummins Diesel engines was a 0-300 psig pressure transducer measuring rail pressure at the fuel pump outlet. The transducer used was a Viatran Model 218-12 strain-guage type. Rail pressure is the measurement of fuel pressure present in the fuel manifold to the engines fuel injection valves. This pressure varies as a function of throttle movement which in turn controls fuel pump pressure. Rail pressure is, then, directly relatable to engine horsepower and RPM. 8. Throttle Valve Closure A microswitch, installed on the carburetor throttle linkage was used to sense closed throttle condition. This generated a step function voltage input to the signal conditioner to be recorded in Channel 8 to indicate closed throttle conditions. 9. Engine Temperature To sense engine temperature, a themistor unit, type ID751 (National Laboratories Industries) was clamped to the coolant output header as close to the engine as possible. This unit provided a scaled analog voltage proportional to coolant temperature. G. Support Equipment and Personnel Support equipment used in the execution of the survey can be divided into three categories: 1. Instrumentation, 2. Transportation and, 3. Communications. a. Support Equipment (Instrumentation) Support equipment for the instrumentation ranged in type from standard electronic test equipment (volt meters, counters, function generators, etc.) used in basic trouble shooting and calibration, to a specially designed cathode ray tube (CRT) display used in verifying tape quality. Two heavy-duty chassis dynamometer were used in the vehicle calibration procedure. A listing of the major pieces of test equipment and their general use has been shown in Table 3. ------- -23- TABLE 3 MAJOR TEST EQUIPMENT REQUIREMENTS Cathode ray tube cassette reader Dead weight pressure standard Function generator Tandom chassis dynamometers Varian model mini computer system Use Tape quality control Fuel pressure transducer cali- bration Calibration of D/A converters (signal conditioners) Horsepower calibration of in- strument installations 1/4 to 1/2 inch tape conversion ------- -24- B. Support Equipment (Transportation) Seven (7) vehicles were used to support the Los Angeles program: two (2) equipment, vans, three (3) leased passenger cars, and two (2) General Service Administration (GSA) cars. A total of fifty-four thousand miles was driven in the vehicles during the program. The vans were equipped as portable instrument labs and carried a complete set of test equipment used in the service, maintenance, and calibration of the on-board recorders. These vehicles were primarily used during installa- tion and maintenance operations, but were sometimes used as backup vehicles for servicing. Four of the five passenger cars were used as chase vehicles which meant they were the prime mode of transportation used when a test vehicle developed trouble while in the performance of its normal work duties. These vehicles were also used for performing normal on-board instrument servicing such as changing tape cassettes and batteries, and performing in-service checkout. A third use of these vehicles was to transport data tapes to the processing center. The fifth passenger car was used in the management of the program. C. Support Equipment (Communications) As mentioned earlier, the California program was totally dependent on operator participation for its success. In view of this, every effort was made to insure that once a vehicle was instrumented it com- pleted its test period on schedule. One important part of meeting schedules was the ability to respond to any situation which threatened to alter the schedule in any way. To accomplish this, a communication system was put into use which allowed all personnel to be in contact with each other and the program manager in a minimum amount of time (usually five (5) minutes) twenty-four hours a day. An area paging system was employed and each man on the two technical crews used in Los Angeles was given remote pagers. In addi- tion to this, the project manager's vehicle was equipped with a mobile telephone which allowed him to communicate with any crewmember while en- route to or from any trouble spot. On-board observers could, using either the paging system or calling the mobile operator, contract any key survey personnel at any time to report problems with in service test vehicles. D. Personnel The personnel requirement for the Los Angeles survey consisted of technical as well as unskilled individuals. Two (2) crews of four qualified test technicians were used for equipment maintenance and installation. Five non-skilled persons were employed to act as on- board observers. Their responsibilities included operational monitoring of test equipment, manual input of selected data, and the manual record- ing of route information. In addition to these tasks, the observers were used as runners for tape delivery, parts and equipment pick-up, and general program assistance. ------- -25- e. Program Logistics In addition to the responsibility of arranging for the acquisition of test vehicles, OLI was also responsible for the program logistics. The question of logistical control was given highest consideration early in the program because of the early recognition of the problem of owner and program manager relations. The necessity for fast turnaround on re- quest for equipment and personnel demanded that normal delays in these areas be reduced to bear minimums wherever possible. The use of OLI for purchasing, manpower acquisition, payroll administration, equipment ren- tals etc. proved to be the soundest approach to on-time completion of the program. Normal governmental channels would not have allowed this. ------- -26- III. Data Collection , A. Type of Data As previously mentioned, the CAPE-21 data base was intended for use in the development of heavy-duty test cycles for engine and/or chassis dynamometers. The optimum goal in the cycle development program was to develop cycles which are representative of the way heavy-duty vehicles are operated in normal service. To accomplish this, the Los Angeles portion of the CAPE-21 study was conducted using commercially owned and operated vehicles selected at random and operated in the normal service of the company by the company's normal drivers. Every precaution was taken to prevent interference with the operation of the driver of the vehicle during the survey period of a given vehicle. The primary data collected in the survey were that data which were considered vital to the testing of emission characteristics of heavy-duty engines or vehi- cles. These data consisted of RPM, load factor, and road speed measure- ments. The remaining data collected in the Los Angeles survey were time of day, road type, traffic condition, relative engine temperature, throttle closure, and vehicle identification. It is important that the logic associated with the methodology used in data collection and the type of data collected be reviewed at this time in order to clearly indicate the limits of the data base. 1. Vehicle Identification Each vehicle tested in the Los Angeles survey was assigned an identification number. A complete listing of the vehicles tested in Los Angeles is given in table 4. 2. Time of Day Time of day for operating periods was recorded in hours and minutes from a twenty-four hour interval clock. Since the data scan rate is .864 seconds, the time between minutes for any given scan location can be calculated. The scan rate was also used as a back-up for the normal time channels, hence data tape rejection for time channels was not necessary. 3. Engine RPM Engine RPM was recorded in millivolts at a 10:1 ratio (RPM/milli- volts). Because RPM was a pulse derived signal in all cases, precision calibration of the signal conditioner was achievable by use of a variable frequency function generator and an event/unit time counter (EPUT). Input versus output data was manually recorded during calibration so that crosschecking of the RPM to millivolt conversion could be accom- plished at a later date, should the need arise. ------- -27- TABLE 4 LOS ANGELES TRUCKS BY MANUFACTURER OF ENGINE Manu- facturer Ford Ford Ford Ford Ford Ford Ford Ford Ford Ford Ford Ford Ford IH IH IH IH IH IH IH IH Com. Com. Com. Com. Com. Com. Com. Com. CMC CMC Truck Number 7 10 11 12 16 17 18 19 24 28 35 39 48 Ford Engine CID/Fuel V8-390/G V8-352/G V8-330/G V8-532/G V8-225/D V8-330/G V8-150/D V8- /G V8-361/G V8-391/G V8-391/G V8-534/G V8-361/G International Harvester 8 13 14 21 26 40 43 47 9 20 31 34 37 38 44 46 V-549/G I6-265/G V-304/G V8-345/G V-304/G V-345/G V-549/G V-304/G Commins Engine NTC335/D/855 NTC350/D/855 NH220/D/743 NTC290/D/855 NTC335/D/855 NH250/D/855 NHC250/D/855 NHC250/D/855 General Motors Year 1973 1965 1972 1966 1968 1974 1972 1964 1971 1971 1967 1964 1968 1968 1969 1973 1970 1974 1970 1971 1969 1963 1973 1969 1969 V6-305/G V6-351/G 1970 1970 ------- -28- TABLE 4—Continued Manu- facturer CMC CMC CMC CMC CMC CMC DDAD DDAD DDAD DDAD DDAD DDAD DDAD DDAD DDAD DDAD Dodge Truck Number 4 5 25 30 32 42 6 15 22 23 27A 27 29 41 41A 45 Engine CID/Fuel General Motors V8-350/G I6-250/G V6-305/G V6-351/G V8-350/G V8-366/G Detroit Diesel 8V71/568/D 8V71N/568/D 8V71/568/D 8V71/568/D 8V71/568/D 8V71/568/D 8V71T/568/D 8V71/568/D 8V71/568/D 8V71/568/D Dodge 36 V8-318/G Year 1971 1974 1967 1970 1972 1960 1974 1963 1974 1973 1973 1973 1971 1974 1969 G D Gasoline Diesel ------- -29- 4. Load Factor Load factor measurements taken in the Los Angeles portion of the CAPE-21 program were designed to relate rear wheel horsepower measure- ments to one of three (3) engine parameters depending on the engine fuel system. As discussed in section II F-7, the three fuel systems were: a. Manifold vacuum in the case of gasoline engines, b. Rail pressure in the case of vehicles equipped with Cummins Diesel engines, and c. Rack position in the case of vehicles equipped with Detroit Diesel Allison division Diesel engines. As previously discussed in section E of this report, it was ori- ginally proposed that load factor data recorded during the survey be converted to engine shaft horsepower through the use of math models derived for each vehicle from calibration data on that vehicle; i.e., engine shaft horsepower, can be considered linear to rear wheel horse- power at all RPMs when normalized to maximum power. This proposal was found to be inadequate in later phases of the data analysis program and the final procedure adopted is discussed in two EPA reports on the subject-^ > 4 which deal with the specifics of horsepower modeling tech- niques. 5. Road Speed Vehicle road speed was taken from the speedometer take-off at the vehicle transmission or front wheel take-off in those vehicles so equip- ped. The accuracy associated with this measurement is equivalent to that associated with SAE standards for motor vehicle speed measurement systems. Some vehicles, however, were equipped with two speed uncom- pensated rear-ends which, under normal circumstances, introduce an error in the speedometer, and hence the road speed data. This error was corrected for in the CAPE-21 survey by the use of a road speed compen- sating network, which was manually activated by the on-board observer whenever the axle was placed in high gear by the driver. 6. Road Type Road type information is a manual input accomplished by the on- board observer. Instructions to these observers on the operation of the switches controlling this input included not placing a road type switch in the "on" position until such time as the vehicle was actually on the particular road type indicated by that switch (i.e., freeway, arterial, or local street). This proved to be a most difficult requirement to control from the standpoint of accuracy in total time spent on a parti- cular road type. For example, there is no way to determine precisely where the observer decided to change from one road type to another, ------- -30- i.e., at the on ramp to a freeway or after completing the merge with freeway traffic. Obviously, the total time associated with a given road type will depend on such a decision. Depending on the importance placed on this parameter by a user of this data during data analysis, a certain degree of special editing may be required to insure accuracy levels desired. 7. Traffic Condition Traffic conditions were recorded in the same manner as was road data, that is, it was a manual input. It therefore, is subject to the same limitations in accuracy as the road type inputs discussed in item 6 above. 8. Throttle Position Throttle position is a measure of driver demand rather than true throttle position. The measurement involves a detection system which simply indicates when the throttle is on the low speed stops, i.e., there is no demand for drive power. 9. Engine Temperature Engine temperature is a relative measurement of thermal operating conditions. Because the sensing device was not physically located in the engine coolant system, only temperatures relative to ambient can be relied on, i.e., engine compartment temperatures which are predominantly made up of engine block temperature, but which are effected by temper- atures associated with other devices in the engine compartment. Cold, warm, and hot operations can be identified by establishing cut points in temperature spreads, but assumed accuracies in absolute temperature beyond this is not recommended. B. Data Format The data from the Los Angeles survey were stored on 1/4-inch mag- netic tape cassettes. 1. Signal Levels and Recording Format Data from each transducer were converted to single levels of 0, + or -1 V. The signals from the ten data channels were then multiplexed and converted to Binary Coded Decimal (BCD) form and recorded serially in four bit words, 4 bite/channel, see figure 7. Each data scan con- sisted of 56 words, thirty (30) data words (3 per channel x 10), eight sign words (one per channel except time and vehicle ID), and one pre- parity word and one parity word. The data are recorded in complement format at a density of 150 bits per inch. C. Data Processing Because the format described in Section Bl was not acceptable to ------- -31- •'/V'TAPE BCD 8 DECIMAL CHANNEL Ill II III III +200+815+710-526-000+1 34-000-825+1 11+000 i i i i i i i i i I ! I 234567 89 10? I DATA SCAN a: Q. IDEALIZED CASSETTE DATA FORMAT ------- -32- FIGURE 8 CASETTE CONVERSION - ZERO SCAN OUTPUT Truck 3 Day 2 I J>0 00058 00004 00001 ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ zzzzzzzzzzzzzzzzzzzzzz 0001 zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzOOOOl zzzzzzzOOOOl zzzzzzzzzzzOOOOl zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz 00001 zzzzzzzzzzzzzzzzzzzzzOOOOl zzzzzzzOOOOl 00001 zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzOOOOl zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzOOOOl zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzz PE 0 RUN 7 SC 34,436 EC 78 ------- -33- most Automatic Data processing machines, a conversion process was re- quired to convert the tape cassettes to, in this case, 9-track IBM com- patible format. During the conversion process a number of tests were performed on the data to establish the acceptability of the'recorded information. These tests did nothing to substantiate the validity of the recorded data, but merely determined if, in fact, the recording format was cor- rect. A test of this type was necessary because 1) the recorder when subjected to electrical noise could write erroneous data bits or char- acters, 2) the parity and/or pre-parity bits could be in error invali- dating a particular data scan; and 3) the recorder had no provisions for read after write operation, and recorded data tapes were susceptible to skew errors caused by read head misregistration. The test performed in the conversion process were: a. "Z" test, this test checked the validity of a scan by checking the parity against the bit count in the scan. If the bit count did not match the parity word the scan was set to zero. The "Z" test, shown in figure 8, simply counted the number of zeroed records in a block of 60 consecutive records and printed a Z if none were zeroed, or the number equal to the total number of zeroed records counted. b. Acceptance criterion check. This test, based on the "Z" test, rejected a tape if the total number of zeroed scans exceeded 10% of the total scans for the tape. c. Readability check. This check consisted of dumping every 20th record to insure that the transcription process was producing a good IBM tape. One additional task was performed during data processing, that task consisted of adding a header to the IBM tape which identified the vehicle by test number, indicated the number of days the vehicle was to be tested, and indicated the type of vehicle, i.e., Diesel or gasoline, number of cylinders, and the license number of the vehicle. D. Data Tape Quality Control To insure delivery of the best possible quality in data tapes to the processing center, a quality control process was used to allow rejection or acceptance of data tape cassettes in the field. The quality control procedure was also used as a diagnostic tool for iso- lating problems in instrumentation as well as personnel errors. An on-board observer was assigned to each test vehicle. The ob- server was present at instrument installation and remained with the vehicle throughout testing. During testing it was the responsibility of ------- -34- each observer to read and manually record each data channel every thirty minutes. Because the readings taken from the recorder display did not reflect what was being written on tape (the recorder did not have read after write capability), a cathode-ray tube (CRT) display system was used to read each cassette after a days running. The CRT's electronics were programmed to read each scan of data and display that line, then when the parity word was read the CRT retraced and began writing the next scan of data directly under the first. If for any reason the parity word was incorrect there would be no retrace and the next line of data would be displaced indicating an error. Since the time channel could be used for locating any point in the data within 51 seconds (seconds were not recorded), the observer's log could be used to verify the approximate data that should have appeared on tape at a given time. Using the CRT and the observer log, data tapes were checked after each days run. If for any reason the tape was found to be defective a decision was made as to what course of action could be taken to prevent loss of the vehicle to the survey, or the instrumenting of a new vehicle waiting for an entrance into the survey. E. Resultant Data Base At the end of the Los Angeles survey fifty-six vehicles were tested, the breakdown of which is: 1. 48 urban operated trucks, 2. 5 city buses, 3. 2 over-the-road (long haul) trucks (not intended for use in cycle development data base) and, 4. 1 over-the-road (long haul) bus. Table 5 shows the final data base description. ------- -35- TABLE 5 Truck Number 1 1 1 1 1 1 2 2 3 3 3 4 4 4 5 5 5 6 6 6 7 7 7 7 8 8 8 8 9 9 9 9 9 10 10 10 10 11 11 11 11 Day Number 4 5 6 7 8 9 2 3 1 3 4 1 2 4 1 2 4 1 2 3 2 3 4 5 1 2 3 4 1 2 3 4 5 1 2 3 4 2 3 4 5 Tape Error* 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Total Zero Scans 154 + 60 206 308 70 116 41 58 56 30 76 38 12 122 46 133 + 60 62 121 78 19 33 66 17 20 22 + 60 914 17 140 102 103 30 1,257 5,715 3,086 357 1,012 37 25 21 730 86 42 Total Scans 23,758 44,446 28,162 26,211 38,328 26,628 19,260 20,228 22,672 16,742 5,008 7,834 17,162 16,809 12,049 5,820 8,070 22,668 18,664 24,771 4,529 23,714 21,624 22,008 29,573 32,074 35,929 31,954 31,648 27,468 27,667 40,110 40,018 11,213 21,918 14,686 13,300 19,897 18,523 17,667 16,378 *Note: If an error on 9-track tape happened during translation, the num- ber of scans appears and 60 scans are added to the total zero scans for every tape error. 1 Record = 60 scans on 1/2 inch 9-track tape. ------- -36- TABLE 5—Continued Truck Number 11 12 12 12 12 13 13 13 13 14 14 14 14 15 15 16 16 17 17 17 17 17 18 18 18 19 19 19 19 19 20 20 20 21 21 21 21 22 22 23 23 24 24 24 Day Number 6 1 2 3 4 1 2 3 4 5 6 7 8 1 2 1 2 1 2 3 4 5 2 3 4 1 2 4 5 6 2A 2B 3 1 2 4 5 1 3 1 2 1 2 3 Tape Error* 0 0 0 0 0 2 1 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 0 0 0 0 0 0 0 0 Total Zero Scans 6 131 139 195 26 6 + 120 77 + 60 77 + 60 25 22 17 11 17 58 48 + 60 17 39 245 12 37 4,451 360 15 88 32 110 19 57 50 11 486 12 993 + 60 33 + 120 25 48 28 72 399 171 497 35 22 269 Total Scans 37,027 18,989 19,260 23,602 22,566 15,253 20,389 13,109 17,172 14,880 12,030 16,044 22,731 22,822 26,409 16,975 27,960 19,687 8,785 17,099 15,263 16,982 13,176 8,360 13,919 7,844 13,369 10,098 14,241 8,045 15,490 1,672 17,365 22,099 15,459 15,684 17,104 42,126 34,938 16,909 20,336 25,586 23,870 19,948 ------- -37- TABLE 5—Continued Truck Day Tape Total Zero Total Number Number Error* Scans Scans 24 4 0 23 25,166 25 1 0 1,384 9,190 25 2 0 19 21,027 25 3 0 2,766 18,388 25 4 0 10 7,751 25 5 0 16 16,187 25 6 0 13 22,212 26 1 0 34 9,250 26 2 0 20 15,827 26 3 0 10 19,095 26 4 0 5 8,009 26 5 1 20+60 12,815 27 1 0 17 21,949 27 2 0 137 11,870 28 1 0 17 6,140 28 2 1 78+60 6,374 28 3 0 118 9,454 28 4 0 86 6,464 28 5 0 116 7,373 28 6 0 77 15,848 29 1 0 86 18,242 29 2 0 88 17,203 29 3 0 26 20,306 29 4 0 171 30,024 29 5 0 15 15,381 29 6 0 33 16,750 30 1 0 332 21,104 30 3 0 47 31,776 30 4 0 238 29,828 31 3 0 19 15,970 31 4 0 13 14,327 31 5 1 28+60 34,032 32 1 0 13 4,872 32 2 0 11 10,354 32 3 0 29 8,445 32 4 0 29 7,287 34 1 0 7 21,876 34 2 0 20 22,802 35 1 0 1,386 15,945 35 2 1 1,335 + 60 15,437 35 3 0 670 15,633 35 4 0 947 21,393 36 2 0 79 15,416 36 3 0 603 18,186 ------- -38- TABLE 5—Continued Truck Number 36 36 37 37 37 37 37 38 38 39 39 39 39 40 40 40 41A 41A 41 41 42 42 42 42 43 43 43 43 44 44 44 44 44 45 45 45 45 45 46 46 47 47 47 47 Day Number 4 6 1 2 3 4 5 1 3 1 2 3 4 1 2 3 1 2 2 3 2 3 4 5 1 2 3 4 1 2 5 7 11 3 4 5 6 7 1 2 2 3 4 5 Tape Error* 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 1 0 0 1 0 0 0 Total Zero Scans 6 43 66 142 25 103 10 119 47 24 + 60 21 217 23 21 322 144 808 25 34 3,596 4,160 43 22 30 1,817 1,151 492 838 12 18 46 9 222 41 102 40 13 + 120 463 + 60 48 169 43 + 60 641 63 16 Total Scans 23,409 7,496 24,606 29,331 26,279 28,541 37,141 11,645 3,895 25,631 27,628 12,202 21,228 13,580 13,029 13,377 15,857 12,476 13,295 18,696 10,358 8,618 7,903 9,469 36,329 12,274 11,556 13,239 6,215 10,356 12,951 6,546 14,439 15,174 25,914 40,256 38,156 27,471 14,727 17,645 10,952 19,554 15,862 16,941 ------- -39- TABLE 5—Continued Truck Numbei 48 48 48 48 48 51 51 80 85 85 85 85 85 85 85 Day Number 1 2 3 4 6 1 2 1 1 2 3 4 5 6 7 Tape Error* 0 1 0 1 2 0 1 0 0 0 0 0 0 0 0 Total Zero Scans 159 52 + 60 25 28 + 60 37 + 120 36 25 + 60 36 61 42 19 50 44 99 18 Total Scans 14,582 10,560 14,441 9,273 17,809 21,437 23,089 35,896 15,324 38,363 35,640 19,459 41,146 31,600 33,816 Bus Number 90 90 90 91 91 91 92 92 92 93 93 94 94 94 95 95 Day Number 1 2 4 1 2 3 3 4 5 1 2 2 3 1 1 2 Tape Error* 0 1 0 0 0 0 1 1 0 0 0 1 0 1 0 0 Total Zero Scans 403 24 101 78 48 152 51 + 60 20 + 60 209 77 93 102 + 60 166 199 + 60 32 5 Total Scans 17,468 24,418 25,560 58,658 57,658 56,808 45,469 12,298 40,058 50,167 49,707 46,725 43,084 44,693 84,198 19,408 ------- -40- IV. Summary The combined, New York and Los Angeles CAPE-21 data base, repre- sents the most comprehensive in-use heavy-duty truck study ever under- taken by any segment of the heavy-duty truck industry. There are still those who would comment that it is not complete. In any study of this magnitude, cost is the greatest restrictor to completeness, as was true in this case. The data collection, in the case of the CAPE-21 study, was confined to the needs of EPA for a data base designed for use in cycle development for heavy-duty truck testing. From this standpoint, the major parameters of interest were engine RPM, load factor, and vehicle speed. Other parameters measured during the survey may be used separately or in conjunction with the primary parameters, but only with a great deal of discretion. Every possible precaution has been .taken to insure that the data collected was of exceptional quality and presented in its purest form. But this is not to suggest that it was intended for use in all phases of heavy-duty truck testing or development. As previously mentioned, this report deals only with the particulars of data collection, the analysis of the collected data is the subject of another report, and will be presented at a later date. For this reason no reference has been made to any conclusions as to the validity of the data or its ability to meet the requirements of the cycle development goals of EPA. ------- LIST OF REFERENCES 1. Heavy Duty Vehicle Driving Pattern and Use Survey: Part I. New York. EPA Report APT. D-1523, Wilbur Smith and Associates, May 1973. 2. Heavy Duty Vehicle Driving Pattern and Use Survey: Part II. Los Angeles Basin, EPA Report EPA-460/3-75-005, Wilbur Smith and Associates, February 1974. 3. Engine Horsepower Modeling for Gasoline Engines, EPA Report HDV 76-04, Leroy Higdon, December 1976. 4. Engine Horsepower Modeling for Diesel Engines, EPA Report HDV 76-03, Chester J. France, October 1976. ------- |