Maroon Creek roundabout

What you are watching. Vehicles entering a roundabout must wait for a gap in the circulating stream of at least about 4.5 seconds, then each following vehicle needs a further 2.7 seconds within the same gap. Those are the standard values used in capacity analysis. Every town car circulating past the upvalley entry is a gap that upvalley traffic does not get, which is why a few hundred short local trips behave like a stop sign for a much larger flow.

What is assumed. Leg bearings are taken off the aerial photograph of the junction: Highway 82 arriving from the upper left, Aspen and Castle Creek Bridge to the right, Maroon Creek Road and the hospital dropping away to the lower left. CDOT describes the junction as the intersection of CO 82, Maroon Creek Road and Castle Creek Road. Circulation is counterclockwise, so anyone leaving Aspen for either the schools or the hospital runs most of the way round the ring and crosses the Highway 82 entry to do it. The hospital stream is drawn but deliberately excluded from the figures, because no count of it exists. Real turning-movement counts for this junction would replace the assumed circulating volume and settle the exact numbers. Arrival rates come from the Coalition report's 1,400–1,600 vehicles per hour upvalley demand and the Jacobs 2024 count of 615 drop-offs, 43 percent of them town residents returning through the roundabout.