US 15 sign

US 15 sign

​Project Includes New Concrete Bridge Deck and Reinforced Support Beams

(December 1, 2021) – The Maryland Department of Transportation State Highway Administration (MDOT SHA) will begin a project starting at 7 a.m. on Friday, December 3, to rehabilitate the bridge on northbound US 15 (Catoctin Mountain Highway) over MD 77 (West Main Street) and Hunting Creek in the Thurmont area of Frederick County. The $5.1 million project is expected to be complete in spring 2023.      

“This project is another example of MDOT SHA’s commitment to infrastructure improvements and safety,” said MDOT SHA Administrator Tim Smith. “Rehabilitation of the aging bridge will result in a smoother driving surface for motorists and reduce the need for costly future maintenance.”      

The bridge was built in 1957 and is nearing the end of its service life. Work includes replacing the bridge deck (concrete surface), repairing the steel beams that support the deck, strengthening the concrete bridge support piers, and cleaning and applying new paint to the structural steel.       

MDOT SHA will maintain traffic on this section of northbound US 15 throughout the project’s duration; however, the bridge will be reduced from two travel lanes to one. MDOT SHA will close one lane so crews can safely remove and replace the deck on that side. When the work is complete, that travel lane will reopen, and the other lane will close for the same work. Work on each side of the bridge should take six to eight months to complete.       

During construction, the exit ramps for MD 77 will remain open. Traffic on MD 77 may experience occasional single-lane closures on weekdays between 9 a.m. and 3 p.m. Bicycle traffic on northbound US 15 will be detoured via Thurmont Boulevard, MD 806 (Frederick Road), Water Street and MD 77. Southbound US 15 will not be affected.      

MDOT SHA will make every effort to complete this project as quickly as possible. Clearwater Construction Inc. based in Mercer, PA, is performing the work. Learn more about the project by clicking HERE.         

MDOT SHA works hard to maintain safe traffic mobility in work zones for our crews as well as our customers.  Drivers need to stay alert, focus on driving and look for reduced speed limits, as well as other driving pattern changes. Please drive like you work here and slow down in construction zones. Motorists can dial #77 on their mobile device for roadside assistance. 

For a list of all major MDOT SHA projects, go to Project Portal. Visit our homepage at For a look at real-time traffic conditions, go to

Editor’s Note

From intersection improvements to widening and new interchange construction, MDOT SHA is investing in projects to enhance the commute and daily travel for millions of Marylanders.  MDOT SHA maintains more than 2,500 bridges and 17,000 miles of non-toll state roads – the interstate, US and state numbered routes in Maryland’s 23 counties.