The research conducted under this project made substantial progress in understanding the driver information overload problem and developed a general model that captures the primary aspects of the problem.

Drivers are typically confronted with a multitude of traffic control devices displaying regulatory, warning, and guidance information. Closely spaced and complex sign arrays cause drivers difficulty as they attempt to navigate while still coping with traffic interactions, lane and speed maintenance, lane change maneuvers, and other aspects of the driving task. The result may be missed information, routing errors, traffic conflicts, and unsafe driving actions such as abrupt maneuvers or inappropriately slow speeds. Unfortunately, there exists little guidance as to what constitutes too much information, how the problem can be detected, and what can be done to improve the sign system at a particular site.

This research developed a conceptual driver information model for analyzing driver information overload. Two research experiments provided an empirical basis for certain aspects of this model. However, at the conclusion of the project, the model remained primarily conceptual. Additional data to refine and validate the model and develop it into a quantitative tool are being collected under NCHRP Project 3-50(02).