Highway Research Record

Environmental Impact of Road Transport

Date of Start:April 2003
Central Road Research Institute (CRRI), New Delhi (R, I)

Present Status and Progress
The project has following distinct objectives:
• Preparation of revised environment impact assessment (EIA) guidelines for roads and highways (Task P-I )
• Simulation of urban road traffic and environment (Task P-II)
• Evolving appropriate emission factors for line sources in urban areas (Task P -III )
• Application of Advanced Pollution Dispersion Modelling System (APDMS) for apportionment of air quality to line sources (Task    P -IV )

Progress made so far
• Critical review of available national and international EIA guidelines has been accomplished.
• Selection of study area and coding of road network (using GIS) is under progress.
• Selection of test route and field studies for driving cycle and evolving appropriate emission factors has been completed and   the equipments required for the study i.e.. on – Board Emission Analyser , has been procured and field studies are under   progress.
• Test run/demonstration done with ADMS (Air Pollution Dispersion Model) being used for the development of dispersion   modelling framework suitable for city-specific traffic and meteorological conditions.

Findings/ Conclusions
Though there are certain guidelines prescribed and documented by the Ministry of Environment and Forest (MoEF) and Indian Roads Congress (IRC) for evaluating the environmental impacts of highway projects, these guidelines have limitations due to their qualitative and generalized approach and are inherently incapable of forecasting long term changes. Certain key issues are either missing or overlooked in our Indian context. Therefore, in the present context it becomes necessary to draft a modified set of guidelines specifically dedicated to roads /highways projects.

Motor vehicles possess the principal polluting potential in deteriorating the urban air quality. However, the link (relationship) between tailpipe emissions invariably falls short of explaining the resultant air quality. The shortcoming may be at two levels; mass emission factors, and predictive modeling tools. The vehicle – specific (category/type) mass emission factors derived from simulated laboratory tests (driving cycle), and expert judgment criteria are used for estimation of vehicular air pollution load calculations and as input parameter for predictive modeling. However, the actual driving conditions vary significantly from the standard testing protocol and results in variation in emission estimates. It has been established that the emissions are higher during actual urban traffic conditions. Thus, it is essential to systematically measure the average mass emissions of important (selected) pollutants for selected categories of vehicles on predetermined test route (Delhi as a case study) covering dynamic traffic situations of urban area. Further, as of now, there are no serious studies towards the development of atmospheric dispersion models in India. Efforts should be made to calibrate the models developed elsewhere for Indian conditions or and also to develop indigenous capability in atmospheric dispersion modelling. The model hence developed / calibrated would be capable of addressing the pollutant contributions from different sources so as to arrive at appropriate source apportionment.

Limitations of Conclusions
The emission factors for in - use vehicles by using on – board emission measurement analyzer needs to be determined on the basis of city traffic conditions as prevalent in most of the Indian cities, as against the Delhi -specific traffic conditions presently envisaged, for wider applications.

The proposed EIA guidelines for roads/highways projects needs to be critically examined/reviewed by implementing agencies like MoEF, CPWD, State PWDs and NHAI for its applicability and usefulness under different terrain , land – use and traffic conditions.

Reports / Publications
Vehicular Pollution monitoring at selected Intersections in Delhi, Sponsored by Society of Indian Automobile Manufacturers (SIAM) New Delhi (Draft Report submitted in February 2005)

1. Sharma,N., Chaudhry K.K., and Chalapati Rao C.V. (2004). Vehicular Pollution Prediction Modelling – A Review of the     Highway Dispersion Models. Transport Reviews, 24(4): 409 - 435 .
2. Sharma, N., Chaudhry K.K., and Chalapati Rao C.V. (2005). Vehicular Pollution Modelling In India. Journal of the Institution of     Engineers ( India), 85: 46-63.
3. Sharma, N., Chaudhry K.K., and Chalapati Rao C.V.(2004) Vehicular pollution modelling using artificial neural network     technique. (Accepted for publication in the Journal of Scientific and Industrial Research; JSIR )