(1) Evaluation in Ohio 

About 88% of the actual times recorded for each sign, and for all the signs combined, were within a range of ± 4 min of the predicted time. It is concluded that the real time TIPS represents a definite improvement over any static non-real-time display system. It provides, in general and most of the time, useful and relatively accurate travel time predictions to the motoring public.

(Source: Helmut T. Zwahlen and Andrew Russ, “Evaluation of the Accuracy of a Real-time Travel Time Prediction System in a Freeway Construction Work Zone”, Transportation Research Record 1803, Transportation Research Board, 2002.

(2) Evaluation in Wisconsin 

The message signs are influencing drivers to change their routes. This study suggests that a 10% alternative route selection rate during peak periods is achievable when accurate, up-to-the-minute, information about delay through a work zone is provided and there is an attractive set of alternative routes. By policy, the signs did not explicitly encourage drivers to use alternative routes. Psychometric studies would suggest that a higher alternative route selection rate could have been achieved had drivers been encouraged to do so.

(Source: Alan J. Horowitz, Ian Weisser and Thomas Notbohm, “Diversion from a Rural Work Zone owing to a Traffic-Responsive Variable Message Signage System”, paper presented at the 2003 Annual Meeting of the Transportation Research Board in January 2003, Washington, D.C.