Urban driving patterns - characterisation, variability and environmental implications.

Driving patterns, i.e. the speed and acceleration profiles of vehicles affect exhaust emission and fuel consumption considerably. This project was aimed at investigating urban driving patterns by focusing on the following issues: 1) how to measure driving patterns, 2) measures for the description of driving patterns, 3) identification of characteristics of driving patterns that have significant effects on exhaust emission and fuel consumption, 4) how driving patterns are related to different components of the system: street environment, traffic, vehicle and driver, and 5) a description of driving patterns over a street net. The project is described in six papers. Two investigations were performed using cars equipped with data-logs driven by subjects, the first had an experimental design and the second an observational design. Characteristics of the traffic environment and the drivers were registered in connection with the driving patterns. More than 19,000 driving patterns were described using up to 62 parameters. From these, 16 independent factors de-scribing various dimensions of urban driving patterns were extracted. Measures of accel-eration, power demand, engine speed and gear changing were found to have significant effects on emission and fuel consumption. The street environment was found to affect driving patterns to a large extent. Furthermore, driver characteristics affected driving patterns, and interactions between different conditions were also shown. Means and stan-dard errors of the driving pattern measures are reported for 21 urban street types