Sub-problem 3a: Weaving Analysis

Another thing to note is that the operation of these weaves is constrained, even though they are long and the LOS are A and B. For Type A weaves, the weave has to be possible within an effective width of 1.4 lanes or the weave is constrained. In all four cases examined in Exhibit 4-47, the required number of lanes has been determined to be higher than 1.4 lanes.

The effective length of the weaving section is another important thing to note. There is a signal at the end of weaving section B, where the PM peak traffic is heavy enough that the length of the double-lane queue often extends across the bridge. So, weaving vehicles can’t take advantage of the length of the bridge to make their lane changes. If motorists going north on I-787 wants to join the back of that queue, they must make a lane change before the end of queue is reached.

This raises an important question: what length of weaving section is required to have a reasonable level of service? If we know that value, we can determine if it is shorter than the length of the weaving section beyond the length of the queue at the signal.

Our analysis found that the weaving section required for an acceptable LOS is less than the distance that remains behind queue, therefore, the performance of the weave should be acceptable.