MD 4 sign)
Work Includes Replacement of Weather Sensor
(September 17, 2021) - The Maryland Department of Transportation State Highway Administration (MDOT SHA) will perform routine maintenance along the MD 4 Governor Thomas Johnson Bridge over the Patuxent River at the Calvert/St. Mary’s County line on Sunday, September 19.
Beginning at 6 a.m. Sunday, one of the bridge’s two lanes will be closed to allow crews to safely replace a weather sensor. Crews will alternate traffic using a flagging operation. The work is expected to be completed by 10 a.m., weather permitting. Portable variable message signs will be placed along area state routes to make travelers aware of the closure.
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 slowdown 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
roads.maryland.gov. For a look at real-time traffic conditions, go to
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.