Effect of cooperative merging on the synchronous flow phase of traffic
  Cooperation in merging is introduced by adding interactions between pairs of vehicles in opposite lanes. Simulations with an improved version of the modified optimal velocity model are done for two lanes merging into a single lane. For ~30 seconds prior to reaching the merge region, vehicles in both lanes adjust their headways to create safe distances in front of and behind the merging vehicle. Cooperation prevents the transition from free flow to synchronous flow that occurs for normal merging, provided the merge region is sufficiently large and the total incoming flow does not exceed the maximum possible single-lane flow. No long-range vehicle-to-vehicle communication is required for the type of cooperation considered. 
L. C. Davis