I need to model an arterial street (four lanes) that widens to six lanes within 1,000 feet upstream and downstream of the intersection. There will be three thru lanes in each direction at the signalized intersection. At a point 1,000 feet downstream of the intersection, the traffic in the added lane will need to merge to the adjacent lane to continue.

Question: Will Synchro / SimTraffic model the merge well, and how should I set it up. Is there a report in Synchro that will report the LOS of the merge similar to a ramp termini analysis?

Thanks for your assistance.

Terry Brown
tobe@swcp.com

Hi Terry,

You'll want to do this with a bend node at the downstream location. Depending on how the actual configuration is, you may be able to handle the upstream add with storage lanes (or a bend would also work here). The number of lanes on the downstream link prior to the bend will equal the number of input through lanes upstream. Go downstream past the bend and input 2 lanes for each direction.

SimTraffic will do a nice job with this since the driver logic will change lanes for this lane drop/add. In Synchro, this will not be automatically considered. The user must input a lane utilization factor (Lanes window) to account for unbalanced flow. Otherwise, the default lane utilzation factor will be used.

John.

John Albeck
Trafficware