All oversize loads entering the City of Gaithersburg, located in Montgomery County, must conform to the requirements set by the Maryland Department of Transportation.

In general, any vehicle over 12 feet in width, 14 feet in height, and within the heavy haul weight class (over 80,000 lbs) should obtain an oversize load permit from the Gaithersburg Public Works Department.

Gaithersburg, being part of the larger Washington metropolitan area, has specific regulations to ensure safe passage through its roads, including those near the NIST campus and other industrial areas.

In Gaithersburg, escort vehicles are required for oversize loads exceeding 14 feet in width or 15 feet in height during daytime movements. For nighttime movements, escorts are required for loads over 12 feet in width or 13.5 feet in height.

Local police escorts may be required for particularly large or complex loads, especially those traveling through downtown Gaithersburg or near major intersections like the I-270 and MD-355 interchange. Fees for police escorts vary based on the number of officers required and the duration of the escort.

To apply for an oversize load permit in Gaithersburg, applicants should visit the City's Public Works Department website or contact them directly at (301) 258-6330. Required documentation includes detailed route information, load dimensions, and vehicle specifications.

Gaithersburg requires a permit application to be accompanied by a route survey, especially for loads that may impact major infrastructure or sensitive areas like the Chesapeake and Ohio Canal National Historical Park.

Gaithersburg has time-of-day restrictions for oversize loads, generally prohibiting movement during peak hours (7-9 am and 4-6 pm) on weekdays.

Seasonal restrictions may apply during extreme weather conditions, such as heavy snow or flooding, which can impact roads like MD-117 and I-270.

Certain neighborhoods and historic districts, such as the Gaithersburg Historic District, may have restricted routes to protect local infrastructure and residents.

The base permit fee for an oversize load in Gaithersburg is $150. Additional fees are assessed based on the complexity of the route, the size and weight of the load, and any required escorts or special services.

For example, loads requiring police escorts incur an additional fee of $200 per hour per officer, with a minimum of 2 hours per escort.