Where do you think the most congested intersections are in Montgomery County? Maybe right by the Bethesda Metro? In downtown Silver Spring? University, Georgia, and Veirs Mill in Wheaton? Actually, no. A review of Montgomery County’s 50 most congested intersections found only one inside one of the county’s urban centers.


There are busy intersections in the more car-oriented neighborhoods around downtown Silver Spring, but not in the core. Map by the author.

County planners ranked the 50 busiest junctions for the Mobility Assessment Report, a regular review of Montgomery’s transportation needs. Notably, the report found that the amount of driving in the county has stayed the same since 2002 even while 100,000 new people came in.

The busiest intersection is Rockville Pike at West Cedar Lane in Bethesda, next to NIH and Walter Reed, which had a critical lane volume of 1,957 cars during morning rush hour. In other words, that means that nearly 2,000 cars pass through a single lane of that intersection each morning. In second place is Rockville Pike and Nicholson Lane in White Flint, which is slowly evolving into a new downtown.

Other than that, the top 50 didn’t contain a single intersection in the downtowns of Bethesda, Silver Spring, and Wheaton, in Friendship Heights, or Rockville Town Center. For decades, Montgomery County has had a policy of directing growth to walkable, urban neighborhoods near transit stations with an aim of reducing car traffic.

RankIntersectionCommunityAM CLVPM CLV
1Rockville Pike at West Cedar Ln.Bethesda1,9571,612
2Rockville Pike at Nicholson Ln.White Flint1,2341,929
3Old Georgetown Rd. at Democracy Blvd.North Bethesda1,4231,923
4Darnestown Rd. at Riffle Ford Rd.North Potomac1,0611,898
5Shady Grove Rd. at Choke Cherry Ln.Rockville1,3631,853
6Connecticut Ave. at East-West Hwy.Chevy Chase1,6841,848
7Georgia Ave. at 16th St.Silver Spring1,1221,816
8Great Seneca Highway at Muddy Branch Rd.Gaithersburg1,4641,800
9Frederick Rd. at Montgomery Village Ave.Gaithersburg1,5361,795
10Rockville Pike at 1st St./Wootton Pkwy.Rockville1,7681,610
11East Gude Dr. at Crabbs Branch Rd.Derwood1,7421,211
12Veirs Mill Rd. at Twinbrook Pkwy.Rockville1,4261,721
131st St. at Baltimore Rd.Rockville1,4221,718
14Connecticut Ave. at Plyers Mill Rd.Kensington1,3491,710
15Shady Grove Rd. at Epsilon Dr./Tupelo Dr.Derwood1,7041,403
16University Blvd. at Piney Branch Rd.Silver Spring1,5791,703
17East Gude Dr. at Southlawn Ln.Rockville1,6921,450
18Randolph Rd. at Veirs Mill Rd.Wheaton1,6831,679
19Piney Branch Rd. at Philadelphia Ave.Takoma Park1,2281,680
20Columbia Pike at Fairland Rd.Fairland1,4161,678
21Connecticut Ave. at Jones Bridge Rd.Chevy Chase1,4901,672
22Montrose Rd. at Tower Oaks Blvd.Rockville1,6631,232
23Bradley Blvd. at Wilson Ln.Bethesda1,6601,603
24Falls Rd. at Maryland Ave./Potomac Valley Rd.Rockville1,3841,658
25Georgia Ave. at Norbeck Rd.Aspen Hill1,6561,592
26Frederick Rd. at Shady Grove Rd.Shady Grove1,6471,486
27Colesville Rd. at Dale Dr.Silver Spring1,6041,645
28Shady Grove Rd. at Midcounty Hwy.Derwood1,6441,323
29Clopper Rd. at Waring Station Rd.Germantown1,6361,589
30Montgomery Village Ave. at Stedwick Ln.Montgomery Village1,6331,170
31Connecticut Ave. at Bradley Ln.Chevy Chase1,4151,628
32Georgia Ave. at Forest Glen Rd.Silver Spring1,3181,626
33Colesville Rd. at Sligo Creek Pkwy.Silver Spring1,5081,624
34Georgia Ave. at Columbia Blvd./Seminary Ln.Silver Spring1,5201,624
35Veirs Mill Rd. at 1st St.Rockville1,6101,475
36Aspen Hill Rd. at Arctic Ave.Aspen Hill1,6091,467
37Norbeck Rd. at Muncaster Mill Rd.Aspen Hill1,6091,238
38Columbia Pike at Greencastle Rd.Fairland1,6071,575
39Old Georgetown Rd. at Tuckerman Ln.North Bethesda1,6041,261
40Great Seneca Highway at Quince Orchard Rd.Gaithersburg1,6021,547
41Randolph Rd. at Parklawn Dr.North Bethesda1,6011,165
42Democracy Blvd. at Falls Rd./South Glen Rd.Potomac1,5941,167
43River Rd. at Holton-Arms SchoolBethesda1,5911,358
44Norbeck Rd. at Bauer Dr.Aspen Hill1,5861,329
45Randolph Rd. at New Hampshire Ave.Colesville1,4401,580
46Layhill Rd. at Ednor Rd./Norwood Rd.Olney1,5791,425
47River Rd. at I-495Bethesda1,579957
48River Rd. at Willard Ln./Greenway Dr.Bethesda1,5791,530
49East-West Hwy. at Jones Mill Rd./Beach Dr.Chevy Chase1,0871,574
50Colesville Rd. at Franklin Ave.Silver Spring1,4131,571
Data from the Montgomery County Mobility Assessment Report. CLV = Critical Lane Volume. Click on a column header to sort.

As a result, while these areas do have higher-than-average rates of foot and bike traffic and high rates of transit use, they’re not as congested as more suburban parts of the county. Just 16 of the top 50 intersections were inside the Beltway.

Not surprisingly, some of the busiest junctions are along major commuter routes like Rockville Pike, Connecticut Avenue, and Georgia Avenue. But many are on small, two-lane roads in suburban or rural communities like #4, Darnestown Road and Riffle Ford Road in North Potomac, or #46, Layhill Road, Ednor Road, and Norwood Road near Sandy Spring. These places are spread-out and far from transit, jobs, and other amenities, meaning residents have to drive a lot.


Layhill Road and Norwood Road. Image from Google Street View.

This report shows that if you build places on the assumption that people will drive everywhere, you’ll get a lot of traffic, while if you give people options, you’ll get less. Not everyone may want to live downtown, but those who choose to do so are keeping the roads clear for everyone else.