I-270 Northbound in Maryland (Full Trip)

Traveling northbound on Interstate 270 in Maryland from the Outer Loop of the Capital Beltway (I-495) in Bethesda to US Route 40 westbound / US Route 15 northbound in Frederick.

The existing expressway now signed as I-270 was originally constructed in the mid to late 1950s. When it opened in 1960, it received the "US-240" designation, which was prior assigned to what is today Maryland Route 355. A few years later, with the creation of the Interstate Highway System, US-240 would receive the concurrent designation of "I-70S". Through the 1960s and 1970s, plans were being developed that would extend "I-70S" to run concurrent with I-495, which would then turn south inside the Beltway running alongside Sligo Creek. "I-70S" would ultimately terminate on I-95 near what is now the Fort Totten Metro Station. Both I-70S and I-95 inside the Beltway were ultimately canceled due to resident opposition. In 1972, the "US-240" concurrency was removed and "I-70S" was renamed to "I-270" in 1975.

Alongside I-95 from the Beltway to Fredericksburg and I-66 from the Beltway to Haymarket, the I-270 corridor as a whole is considered one of the worst congested highways in the DC area outside the Beltway. A particular problem I-270 is known to suffer from is severe bottlenecks, or sudden lane drops. In the course of just fifteen miles from Rockville to Clarksburg, I-270 drops from thirteen lanes to a mere four. This, combined with I-270's four-lane segment from Clarksburg to Frederick exceeding capacity, is the main reason I-270 sees severe congestion frequently. (This video actually captures an infrequent moment where there is no significant congestion.)

Exits and Landmarks:
0:05 I-495 (Capital Beltway) / MD-355 (Rockville Pike){Southern Terminus}
1:42 MD-187
1:50 Rockledge Drive
2:20 I-270 Spur
3:48 Begin Thru/Local Lanes
4:04 Montrose Road
5:36 MD-189 (Falls Road)
6:30 MD-28
8:18 Shady Grove Road
9:06 I-370 / MD-200 (Intercounty Connector) / Sam Eig Highway
10:46 MD-117
11:04 MD-124
11:48 Watkins Mill Road / End Thru/Local Lanes
16:32 Middlebrook Road
14:02 MD-118
15:00 MD-27
17:32 MD-121
21:04 MD-109
22:42 "Cutie Fountain"
23:26 Bennett Creek
24:30 MD-80
26:44 Scenic View
27:58 Monocacy River
29:02 MD-85
30:00 I-70
31:06 US-40 {Northern Terminus}
31:34 US-15 (Catoctin Mountain Highway) / US-340

Southbound:    • I-270 Southbound in Maryland (Full Trip)