San Ildefonso roundabout: peak volume and capacity |
<< Previous |
Right: Partial schematic showing notation used for traffic volume data below. Each lane is represented by a letter (A-D) and a direction (in or out of circle). |
The traffic volumes below are derived from video-tapes
I made during the morning commute on 4/20/2011. |
Above: Traffic volume for the various components of the roundabout. | Above: Traffic volumes for the circle (A-in + B-in + C-in + D-in) and for the circle plus Bypass-DA. To compare these volumes with other roundabouts, make sure to understand what traffic conditions apply and what components are included. |
The capacity estimated from the simple model discussed previously is about 1500 cars per hour. The peak seen here for the circle (excluding the bypass) is about 1100 cars/hr, so the utilization is roughly 70%, which seems plausible, given the qualitative features of the roundabout's actual performance. |
<< Previous |