We utilise two different technologies for Journey time surveys depending on the data set required.
ANPR camera based surveys where we log the registration number at point A at time T and again at point B at time T1. ANPR surveys will collect data from over 90% of the vehicles on the route so are used when the traffic model requires a high level of individual data points.
Alternatively we use Bluetooth and Wi-Fi sensing; where we will register only around 25% - 30% of the vehicles (the others don't have the RF signals in operation). Bluetooth equipment is both significantly cheaper and easier to set up than ANPR so if a statistical result is acceptable then this is a more cost effective solution.