New methods for measuring and interpreting traffic data enable analysis of local traffic conditions at unprecedented levels of detail. Researchers can use this to design systems tailored to specific traffic environments that lessen congestion without adding infrastructure.

Techniques include:

• ramp metering,
• signal priority systems for transit, and
• other adaptive control technologies.

Test sites are located within congested freeway systems and urban street networks controlled by traffic signals. From these, researchers generate more general guidelines for enacting congestion mitigation policies suitable for a large number of sites.