Samenvatting
A new method is developed for travel speed surveys in which location and speed data are collected continuously by car navigation systems on probe vehicles. By aggregating these individual data, link speed data and origin-destination data are obtained. In order to determine the relationship between the number of probe cars and the performance of the new travel speed survey system, a simulation system was developed. Simulation studies indicated that 0.3% of total cars are necessary to obtain travel speed survey data for every hour during daytime on roads with a traffic volume of 30,000 cars, with additional survey cars required at lower traffic volumes.