Sub-problem 4b: Clifton Country Road PM peak hour - Existing Conditions

Notice that we can drop the eastbound and westbound RTOR values to zero and the intersection still functions well. Neither of these right turns has catastrophic increases in delay. The eastbound right-turn delay grows from 14.0 to 14.5 seconds per vehicle. The westbound delay grows from 13.1 to 16.3 seconds per vehicle. The base case assumes that these auxiliary lanes are reachable, meaning that the length of the eastbound lane must be 10-20 cars long to be reachable 50-95% of the time, and the westbound lane must be 10-19 cars long.

For the northbound approach, however, the RTOR value cannot drop to zero without creating LOS F. In fact, the smallest feasible RTOR value is 297 vehicles. That means, of the 508 northbound right turns, 58% (297/508) must be able to make a RTOR to make the intersection work. The intersection currently operates this way; no standing queue exists in that lane.