Lane Alignment is a simple, but important, calibration parameter for SimTraffic. This setting controls how the approach lane(s) align with the receiving lanes at an intersection, and is particularly important for locations with more receiving lanes than approach lane(s). Edit this setting in Synchro's Simulation Settings window; there are four possible choices:
- Left
- Right
- L-NA (left, no add)
- R-NA (right, no add)
There are many scenarios where this setting can be useful. Here we will discuss one example of an interchange exit-ramp. Notice how all of the westbound left-turn vehicles are using the right lane:
The reason for this behavior is evident after reviewing the Intersection Paths. Turn on this view in Options>Map Settings. Notice how the westbound left-turn lane aligns with the southbound left-turn lane. This file is setup without any "U-turn" volume from the WBL to SBL, so vehicles are avoiding this lane. Changing the Lane Alignment to R-NA resolves this issue, as seen below. |
And finally, here is the resulting SimTraffic file with more balanced lane utilization.