Dutta, N., et al.
Benefit Summary HTML

This Phase II project evaluated the performance of an Active Traffic Management System (ATM) system installed on I-66 in Northern Virginia. An operational analysis was conducted from October 2015 through November 2017 and a safety analysis was conducted from October 2015 through December 2016.

In early 2013, construction began on a Virginia Department of Transportation (VDOT) project to install an ATM system on I-66 from US 29 in Centreville to the Capital Beltway. Construction was completed in September 2015 and spanned approximately 12.4 miles. The primary ATM strategies implemented on I-66 included:

  • Variable Speed Limits (VSL): On I-66, the normal posted speed limit is 55 mi/h, but the VSL system can post speeds between 35 mi/h and 50 mi/h above each lane depending on traffic conditions.
  • Hard Shoulder Running (HSR): The I-66 HSR system dynamically opened or closed the shoulder lanes depending on roadway conditions.
  • Lane Use Control Signals (LUCS): For incident and work zone management, overhead gantries were deployed with LUCS to alert drivers to lane blockages.


A segment-level analysis was performed to determine the segments that had benefitted the most from the implementation of the ATM system.

Hyperlink Exit Door
Last Modified Date
Other Reference Number
VTRC 19-R7
John Hicks
Priority Research Area
Publication Sort Date
Virginia DOT
Result Type
Source ID
Evaluation of the Impact of the I-66 Active Traffic Management System: Phase II
Source Review
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