With an overview of the various supply measures and a review of their effectiveness, we will briefly summarize the issue of congestion reduction and some implementation obstacles which have to be considered during the application of these strategies.

The actual reduction of congestion and vehicle delay can draw upon a wide array of strategies and measures designed for different aspects of the problem. These measures can be classified into five basic categories: supply management using TSM, additional capacity provided by new construction, highway reconstruction, demand management using both TSM and TDM, and, finally, advanced technologies. It is important to recognize the following:

No single strategy can effectively reduce all aspects of congestion;

A balanced approach of supply strategies (protecting and expanding capacity) and demand strategies (reducing the need to travel and modifying the time of travel) must be used to effectively reduce congestion;

TSM supply measures (low-cost improvements, freeway and incident management, lane widening, signal improvements, ramp metering) are very cost-effective and efficient in relieving recurring and non-recurring congestion; and

Advanced Technologies such as [VHS will be effective tools in alleviating congestion in the future.