MDOT SHA LogoMDOT SHA Traffic Alert - Lengthy Closure Likely on US 1 (Washington Boulevard) between Old Washington Road and Montgomery Road in Elkridge, Howard County. ue to a gas line that was damaged, US 1 (Washington Boulevard) will be closed for a lengthy duration, possibly well into Friday. MDOT SHA recommends that motorists detour off onto MD 100 to either MD 295 (Baltimore-Washington Parkway) or I-95 to I-195 and back to US 1. Real-time traffic – www.md511.org.