Work out level of service estimate instantly with clear inputs, formula shown and shareable results.
Level of service grades traffic conditions from A to F using the volume to capacity ratio. Below 0.35 drivers are essentially unaffected by others; above 0.85 small increases in demand produce large increases in delay; above 1.0 the facility has broken down and queues grow until demand falls.
Volume to capacity ratio
v/c = demand flow / (capacity per lane x lanes)
Level of service bands
A up to 0.35, B to 0.50, C to 0.70, D to 0.85, E to 1.00, F above
v/c = demand flow / (capacity per lane x lanes). Level of service grades traffic conditions from A to F using the volume to capacity ratio.
Because building for free flow in an urban area requires land and cost that cannot be justified, and induced demand fills it anyway. Urban design targets are usually D or E at peak.
This calculator takes 3 inputs: Demand flow, Capacity per lane, Number of lanes. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.