List of highways numbered 100
Several highways are numbered 100:Australia
- Great Ocean Road, Victoria
- Surf Coast Highway, Victoria
- Lincoln Highway, South Australia
- Flinders Highway, South Australia
Canada
- Alberta Highway 100
- Manitoba Highway 100
- New Brunswick Route 100
- Newfoundland and Labrador Route 100
- Niagara Regional Road 100, Ontario
- former Highway 100
Costa Rica
- National Route 100
Croatia
- D100 road
Germany
- Bundesautobahn 100, the Berliner Stadtring
- Bundesstraße 100
India
- National Highway 100
Korea, South
- Seoul Ring Expressway
Malaysia
- A100 road, a road in Perak
- Federal Route 100, a highway bypass in Manjung district, Perak
Mexico
- Sonora State Highway 100
Netherlands
- Stadsroute 100, the city center ring road
Poland
- Voivodeship road 100 in the Pomeranian Voivodeship
Serbia
- State Road 100, an IIA-class road connecting Horgoš with Batajnica.
Turkey
- State road D.100, a west–east state road running from the Bulgarian border to Iranian border.
United Kingdom
- , part of the London Inner Ring Road
United States
- Alabama State Route 100
- Arkansas Highway 100
- California State Route 100
- Colorado State Highway 100
- Connecticut Route 100
- Delaware Route 100
- Florida State Road 100
- Georgia State Route 100
- Illinois Route 100
- Indiana State Road 100
- Iowa Highway 100
- K-100
- Kentucky Route 100
- Louisiana Highway 100
- Maine State Route 100
- Maryland Route 100
- * Maryland Route 100
- * Maryland Route 100
- * Maryland Route 100J
- * Maryland Route 100L
- * Maryland Route 100M
- * Maryland Route 100N
- * Maryland Route 100O
- * Maryland Route 100P
- * Maryland Route 100Q
- * Maryland Route 100R
- * Maryland Route 100S
- * Maryland Route 100T
- * Maryland Route 100U
- * Maryland Route 100V
- * Maryland Route 100W
- * Maryland Route 100X
- M-100
- Minnesota State Highway 100
- Missouri Route 100
- Nebraska Highway 100
- New Jersey Route 100
- * County Route 100
- New York State Route 100
- * County Route 100
- * County Route 100
- * County Route 100
- * County Route 100
- * County Route 100
- North Carolina Highway 100
- Ohio State Route 100
- Oklahoma State Highway 100
- Pennsylvania Route 100
- Rhode Island Route 100
- South Dakota Highway 100
- Tennessee State Route 100
- Texas State Highway 100
- * Texas State Highway Spur 100
- * Farm to Market Road 100
- * Texas Park Road 100
- Utah State Route 100
- Vermont Route 100
- Virginia State Route 100
- Washington State Route 100
- West Virginia Route 100
- Wisconsin Highway 100
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