I have two parallel links (with the same link length) – one is for general traffic and the other is an adjacent bus-only link. Having looked at the relative cruise times I have noticed that despite accounting for different crusie speeds and the bus stopped- time there is still a discrepancy in the cruise times shown in the output. Why is this?
On top of the user-specified standing time of the buses on that particular link, TRANSYT adds on additional time (to the cruise time) to account for the deceleration and subsequent acceleration back up to the cruise speed on links that have bus stops. This time depends on the link length and cruise speed specified. E.g. the time taken to accelerate and decelerate is deemed to take about 16 seconds as long as the link can fully accommodate this manoeuvre within its length. For short links this time will not be accommodated and hence the additional time lost due to acceleration/deceleration will be less as a result. With a specified cruise speed of 30 km/h on a link which is over 60 metres long, this extra time is close to 9 seconds.