A different exit numbering system, like the one already in place on Interstate 395, is being installed on Route 2 and Route 11 to make it easier for drivers to understand how far they’ve come and how far they need to go.

The milepost-based exit signs mean the first exit off Route 2, which is located about a mile from the origin of the highway in downtown Hartford, will become exit 1A. The final exit in Norwich will become exit 38 because that’s how many miles it is from the starting point.

Some of the new signs have already been installed. State Department of Transportation spokesman Josh Morgan said the dark bags covering the new numbers will be removed once all the updated signs on each route have been erected. He could not say when that will happen.

The old exit numbers will remain on the signs for about two years so people can get used to them, he said. It also gives businesses and organizations time to update directions in any advertising materials.

The I-395 project was completed in 2015. The final interstate in Connecticut to be renumbered will be I-95 in 2028, according to the DOT.

Morgan said the push will ensure the state’s numbering is consistent with highways throughout the rest of the country. Going with the milepost-marker system makes it easier for drivers and emergency responders to navigate the road, he said. It also streamlines the process if the agency adds future exits because existing ones won’t have to be renumbered.

The upgrades are part of a larger project to give new numbers to exit signs on Routes 3 and 17 as well.

A $17.2 million contract was awarded to Danbury-based A.M. Rizzo Electrical Contractors Inc. to install the signs on Routes 2, 3, 11 and 17. The project is covered by a mix of federal and state funds.

The project is a response to federal requirements going back to the 2009 edition of the Manual of Uniform Traffic Control Devices for exit numbers to match mile markers. The manual said continuity across the highway system “provides valuable orientation” for drivers.

A timeline from the DOT shows Interstate 291, Route 8 and Route 15 will be renumbered in 2025, followed by Interstate 384 in 2026, Interstate 91 in 2027 and Interstate 84 in 2028.

He said the highways were prioritized for renumbering based on factors including the age of the current signs and whether or not there was other work being done that could incorporate the sign improvements. He pointed to signs installed earlier this year on Interstate 691 in conjunction with highway improvements and bridge work spanning Meriden to Cheshire.

He said the agency is holding off on renumbering Interstate 95 because the signs along the route are in relatively good condition. Plus, there’s the possibility of incorporating the replacement work into a larger project down the road.

A large planning study was launched a year ago to identify ways to improve I-95 from Branford to the Rhode Island state line. A report expected next year will identify early-, mid- and long-term projects to be implemented over the coming decades. The state has already identified the proposed reconfiguration of exits 71 and 72 in Old Lyme and East Lyme as a candidate for “early action” in 2028.

Completion of the ongoing $148 million exit 74 reconstruction project in East Lyme is expected in 2027.

e.regan@theday.com