Starting next month, Northern Virginia drivers will see new electronic message signs displaying estimated travel times to certain destinations. These are similar to the travel time displays that drivers now see on Maryland highways, but the ones scheduled to begin operation Aug. 15 on Interstate 66 between Gainesville and the Capital Beltway will be the first from the Virginia Department of Transportation.

This will be a two-month pilot project. If VDOT rates the program a success — if the system provides good estimates and drivers find them helpful — it will be expanded to other Northern Virginia Interstates and eventually to highways throughout Virginia.

The Federal Highway Administration has been encouraging states to display travel times on their electronic message boards when the boards don’t need to display information about traffic incidents ahead.

Not only do individual motorists find them helpful in planning their routes, they are also a tool in traffic management, the federal administration says.

This is the type of sign that might say something like, “Beltway, 17 miles, 17 minutes.” That’s easy for drivers to absorb, and I haven’t noticed drivers slowing down for such messages any more than they might for those “Report Suspicious Activity” signs with a phone number you’d have to memorize.

If drivers see “17 miles, 17 minutes,” drivers feel reassured, and less stressed about the trip ahead. They know it’s a pretty safe back to stick with that highway. If they see the number of minutes go way up, they know there’s trouble ahead.

In theory, that enhances the overall management of the traffic system. Drivers who stick with that highway may be more alert for trouble ahead. Drivers who divert to other highways will be putting the road network’s capacity to better use.

That’s the theory, at least. Many highway drivers either don’t know what the alternatives are or are reluctant to depart from the big road for one that might prove at least as congested.

Given the state of traffic congestion along I-66, especially near the Beltway in the morning, I wonder how many drivers will see a travel time sign and just decide to turn around. At least that would free up some extra road capacity.

Here are the three initial locations for the travel-time signs:

— Eastbound I-66, just east of Route 28, displaying travel time to the Beltway.

— Westbound I-66, just west of Route 50, displaying travel time to Gainesville.

— Westbound I-66, just west of Route 7100, displaying travel time to Gainesville.

The travel times will be displayed weekdays from 5 a.m. to 9 p.m. and weekends from 8 a.m. to 8 p.m.

VDOT says it will be using data from INRIX, a compa­ny that pro­vides live­ traff­ic information,­ and other sources to determine the travel times. Traffic controllers at the Public Safety Transportation Operations Center in Fairfax will ensure the travel times are successfully sent to the message signs and are accurately refreshed every five minutes.