Samenvatting
Microscopic traffic data are important for the calibration and validation of simulation models as well as for empirical analyses. This paper reports a comparative study of three different GPS techniques namely a standard GPS device combined with safety record (SR) sensors, real-time kinematic (RTK) GPS and virtual reference station (VRS) to measure the position and speed of four instrumented vehicles participating in multiple car-following and lane changing experiments. The recently introduced VRS technique has significantly improved the range and reliability of the conventional RTK GPS technology, yielding a few centimetre level of accuracy over a wider range. (Author/publisher).