New traffic control methods for mobile work zones and their effectiveness in reducing crashes

New York has developed a set of typical methods for mobile work zone traffic control that try to balance the information needs of the driver with resource realities of maintenance crews.   Its draft typical layouts usually include an advance warning vehicle on the shoulder (with arrowboard where appropriate and a shadow vehicle with a truck-mounted impact attenuator and an arrowboard where appropriate) in the lane protecting the workers. In both mobile and slow-moving operations, the state continues to have impacts between vehicles and the first shadow vehicle in a travel lane and is at a loss for how to prevent these collisions other than to stop doing mobile or slow-moving work.
One concern is that maintenance crews sometimes try to use mobile work zone M&PT set-ups for work that takes more than a brief period and should have signing and channelization.