In Maryland the maximum speed limit posted on Interstate Highways is 70 mph (113 km/h) and the default speed limit is posted at 65 mph (105 km/h). The speed limit on I-68 is posted at 70 mph (113 km/h) except for a seven-mile section around Cumberland. The speed limit on I-70 is posted at 70 mph (113 km/h) from the Pennsylvania state line to MD 180 in Frederick County and from MD 144 in Frederick County to US 29 in Howard County.
Maryland’s urban freeways normally have speed limits of 55 mph (89 km/h), like I-495, or 60 mph (97 km/h), although some stretches are signed for 65 mph (105 km/h) travel such as portions of I-95 and I-97 in and around the Baltimore suburbs. More restrictive limits are found on I-83 south of North Avenue when approaching downtown Baltimore and on I-68 through Cumberland, both sections being marked at 40 mph (64 km/h).
Four-lane non-interstates and non-freeways are posted at 55 mph (89 km/h). This includes the expressway grade roadways like US 50 and US 301 east of the Bay Bridge, US 15 north of Frederick to the Pennsylvania state line, MD 404 around Denton and US 29 between I-495 and I-70.
Normally, speed limit drops are in 5 mph (8 km/h) to 10 mph (16 km/h) increments. However, one speed zone drops from 55 (89 km/h) to 25 mph (40 km/h) along US 301 southbound at the Nice Bridge for the toll plaza.
Two-lane roads are generally posted at 50 mph (80 km/h) but there are a handful of routes posted at 55 mph (89 km/h). It is more common to see 55 mph (89 km/h) on the Eastern Shore and in Frederick and Carroll counties than the Baltimore-Washington corridor and Western Maryland.
Urban and downtown speed limits are generally posted at 30 mph (48 km/h).