49 CFR § 571.500 - Standard No. 500; Low-speed vehicles.
S2. Purpose. The purpose of this standard is to ensure that low-speed vehicles operated on the public streets, roads, and highways are equipped with the minimum motor vehicle equipment appropriate for motor vehicle safety.
S3. Applicability. This standard applies to low-speed vehicles.
(a) When tested in accordance with test conditions in S6 and test procedures in S7, the maximum speed attainable in 1.6 km (1 mile) by each low-speed vehicle shall not more than 40 kilometers per hour (25 miles per hour).
(b) Each low-speed vehicle shall be equipped with:
(2) Front and rear turn signal lamps,
(4) Stop lamps,
(5) Reflex reflectors: one red on each side as far to the rear as practicable, and one red on the rear,
(7) A parking brake,
(9) A VIN that conforms to the requirements of part 565 Vehicle Identification Number of this chapter, and
(12) An alert sound as required by § 571.141.
S6. General test conditions. Each vehicle must meet the performance limit specified in S5(a) under the following test conditions.
S6.1. Ambient conditions.
S6.1.1. Ambient temperature. The ambient temperature is any temperature between 0 °C (32 °F) and 40 °C (104 °F).
S6.1.2. Wind speed. The wind speed is not greater than 5 m/s (11.2 mph).
S6.2. Road test surface.
S6.2.1. Pavement friction. Unless otherwise specified, the road test surface produces a peak friction coefficient (PFC) of 0.9 when measured using a standard reference test tire that meets the specifications of American Society for Testing and Materials (ASTM) E1136, “Standard Specification for A Radial Standard Reference Test Tire,” in accordance with ASTM Method E 1337-90, “Standard Test Method for Determining Longitudinal Peak Braking Coefficient of Paved Surfaces Using a Standard Reference Test Tire,” at a speed of 64.4 km/h (40.0 mph), without water delivery (incorporated by reference; see 49 CFR 571.5).
S6.2.2. Gradient. The test surface has not more than a 1 percent gradient in the direction of testing and not more than a 2 percent gradient perpendicular to the direction of testing.
S6.2.3. Lane width. The lane width is not less than 3.5 m (11.5 ft).
S6.3. Vehicle conditions.
S6.3.2. No adjustment, repair or replacement of any component is allowed after the start of the first performance test.
S6.3.3. Tire inflation pressure. Cold inflation pressure is not more than the maximum permissible pressure molded on the tire sidewall.
S6.3.4. Break-in. The vehicle completes the manufacturer's recommended break-in agenda as a minimum condition prior to beginning the performance tests.
S6.3.5. Vehicle openings. All vehicle openings (doors, windows, hood, trunk, convertible top, cargo doors, etc.) are closed except as required for instrumentation purposes.
S6.3.6. Battery powered vehicles. Prior to beginning the performance tests, propulsion batteries are at the state of charge recommended by the manufacturer or, if the manufacturer has made no recommendation, at a state of charge of not less than 95 percent. No further charging of any propulsion battery is permissible.
S7. Test procedure. Each vehicle must meet the performance limit specified in S5(a) under the following test procedure. The maximum speed performance is determined by measuring the maximum attainable vehicle speed at any point in a distance of 1.6 km (1.0 mile) from a standing start and repeated in the opposite direction within 30 minutes.