An approach to a signal has a saturation flow rate of 1800 veh/h. During one 80-second cycle, there are four vehicles queued at the beginning of the cycle (the start of the effective red) and two vehicles queued at the end of the cycle (the end of the effective green). At the beginning of the effective green there are 10 vehicles in the queue.
The arrival rate is constant and the process is D/D/1. If the effective red is known to be less than 40 seconds, what is the total vehicle delay for this signal cycle?