00771083

Component

https://doi.org/10.3141/1664-05

http://scholar.google.com...sler&publication_year=1999

New vehicle modal emissions rate models will assess emissions as a function of specific operating mode or engine load surrogates. These new models require that vehicle activity be input by fraction of time spent in different operating modes. However, the ability to realistically model on-road modal vehicle activity currently limits the implementation of these models. Few data on how vehicles operate in a real-world setting exist. Simulation models offer attractive advantages for modal modeling. They are readily available and generally can be used with both simple and detailed data input. Simulation models were developed to model the impacts of signal timing, incidents, or design features on traffic flow and perform well for these applications. However, simulation models, such as CORSIM, use theoretical profiles of vehicle acceleration and speed relationships that have not been validated in the field. To determine the feasibility of using simulation models to predict on-road speed-acceleration profiles and to identify potential problems in their use as such, a study intersection was modeled in NETSIM, and the simulation output was compared with data collected from field studies of signalized intersections. Analyses of the simulation output and field data indicate that NETSIM does not adequately simulate instantaneous modal vehicle activity. NETSIM intersection activity shows higher fractions of hard accelerations [>/= 9.7+ km/h/s (6 mph/s)] than are demonstrated by field data for the study intersection. For midblock, the results indicate that field data demonstrate a much greater distribution of speeds and accelerations than the distribution modeled by NETSIM.

This paper appears in Transportation Research Record No. 1664, Energy, Air Quality, and Fuels 1999.

English

p. 40-46

1999

Transportation Research Record

0309070600

Figures (8) ; References (19) ; Tables (3)

Acceleration (Mechanics); Air quality; Computer models; Exhaust gases; Midblock crossings; Signalized intersections; Simulation; Speed; Speed distribution

CORSIM (Traffic simulation model); Netsim (Computer program)

Field data; Operating mode (Engines)

Environment; Highways

TRIS, TRB, ATRI

Oct 5 1999 12:00AM

• APPLYING GREENHOUSE GAS EMISSIONS TRADING TO THE LIGHT-DUTY VEHICLE SECTOR
• ESTIMATING EMISSIONS AND FUEL CONSUMPTION FOR DIFFERENT LEVELS OF FREEWAY CONGESTION
• FORECASTING DYNAMIC VEHICULAR ACTIVITY ON FREEWAYS: BRIDGING THE GAP BETWEEN TRAVEL DEMAND AND EMERGING EMISSIONS MODELS
• FUEL-CYCLE GREENHOUSE GAS EMISSIONS IMPACTS OF ALTERNATIVE TRANSPORTATION FUELS AND ADVANCED VEHICLE TECHNOLOGIES
• INTEGRATED APPROACH TO ENVIRONMENTAL RATING FOR LIGHT VEHICLES
• MARKET BARRIERS TO NATURAL GAS VEHICLES AND THE ROLE OF CLEAN AIR CREDITS
• MODAL-BASED INTERMEDIATE SOAK-TIME EMISSIONS MODELING
• TOTAL ENERGY CYCLE ENERGY USE AND EMISSIONS OF ELECTRIC VEHICLES
• USING VIDEO DATA TO MEASURE VEHICLE OPERATING MODES FOR PREDICTION OF EMISSIONS