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Title: Collection and evaluation of modal traffic data for determination of vehicle emission rates under certain driving conditions. Research report

Technical Report ·
OSTI ID:638551

This report presents a research effort for collecting the on-road vehicle emission data, developing the ONROAD emission estimation model and evaluating existing emission estimation models including the emission factor models MOBILE and EMFAC. The on-road emission data were collected from highway locations in Houston using a Remote Emission Sensor (RES) called Smog Dog, which was developed by the Santa Barbara Research Center (SBRC). The SMOG DOG is used to collect the emission concentrations of CO, HC, and NO{sub x}, as well as to simultaneously record a vehicle`s instantaneous speed value and acceleration/deceleration rates while its emission is detected. During the emission data collection, the ambient temperature and humidity were periodically recorded. The collected emission data are used to develop the ONROAD emission estimation model, which consists of a series of emission estimation equations. In these emission estimation equations, the emission rates are made functions of a vehicle`s instantaneous speed, acceleration/deceleration rate, ambient temperature and humidity. The emission factors that are derived from MOBILE and EMFAC are compared with the collected on-road emission data by emulating the standard FTP driving cycles using the ONROAD emission rates. Efforts are also made to compare the emission estimates in traffic simulation models with the on-road emission data. It is found that traffic simulation models considerably underestimate the on-road emissions, and thus these models are not recommended for use in performing any field vehicle emission analysis.

Research Organization:
Texas Southern Univ., Center for Transportation Training and Research, Houston, TX (United States); Texas Dept. of Transportation, Office of Research and Technology Transfer, Austin, TX (United States); Federal Highway Administration, Austin, TX (United States)
Sponsoring Organization:
Federal Highway Administration, Washington, DC (United States)
OSTI ID:
638551
Report Number(s):
PB-98-149271/XAB; CNN: Contract TDOT-0-1485; TRN: 82022437
Resource Relation:
Other Information: DN: See also PB98-149255 and Final Report, PB98-149263.; PBD: Sep 1997
Country of Publication:
United States
Language:
English