FMCSA Windshield Requirements

by Nikki Van De Walle
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The Federal Motor Carrier Safety Administration, FMCSA was established on January 1, 2000 by the U.S. Department of Transportation. The FMCSA was established to follow the Motor Carrier Safety Improvement Act of 1999 to help ensure that safety standards were being met for vehicles. The FMCSA provides financial assistance for safety programs, conducts research, data collection, analysis and improves technologies, ensures regulatory compliance and enforcement, and develops standards for commercial driver licenses.

Windshield Wipers and Washing System

Vehicles must be equipped with a power-driven windshield wiping system, according to FMCSA. The wiping system must have two speed frequencies and one frequency must reach a speed of 45 cycles per minute according to FMCSA regulations. The other frequency needs to have a variance in speed by at least 15 cycles per minute either faster or slower than 45 cycles per minute without going slower than 20 cycles per minute. The washing system must meet the requirements of SAE International for vehicles that weigh less than 10,000 lb.

Defrosting and Defogging Systems

The FMCSA defrost and defogging system regulations apply to all passenger and multipurpose passenger vehicles, trucks and buses. Every vehicle must have a windshield defrosting or defogging system installed. Defrosting and defogging systems must meet SAE Recommended Practice J902 section 3. Vehicles manufactured outside of the non-continental United States can have either a defogging system that works by dehumidifying the aid inside the passenger compartment or by applying heat to the windshield directly, instead of meeting the standard regulations.


FMCSA regulations apply to passenger and multipurpose passenger vehicles, trucks and buses that have a gross weight rating less than 10,000 lb. Excluding forward control vehicles, walk-in vans or vehicles with fold-down or removable windshields, according to FMCSA. Windshields must not be discolored or damaged with the exception of appropriate tinting, cracks that do not intersect another crack or if it can be covered by a disc of three-quarter-inch in diameter, according to FMCSA. Window tint can only be applied to the right and left of the driver as long as it allows parallel luminous transmittance of at least 70 percent, according to FMCSA. Devices must be mounted six inches below the top of the windshield and outside of the area swept by your wiper blades. All decals must be placed on the bottom or sides of the windshield according to the Commercial Vehicle Safety Alliance, located outside of the area swept by your windshield wiper blades and the decal cannot extend more than 4.5 inches from the bottom of the windshield, according to FMCSA.

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