OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

March 2, 2010

Letter to 20090429-9037

Re: Permissible methods of operating trucks in reverse on construction sites.

Question #1: Does 29 CFR 1926 Subpart O permit an employer to use a rear-mount day/night camera system with in-cab monitoring of the truck's rear instead of a back-up alarm?

Answer #1: Two requirements in 29 CFR 1926 Subpart O, 1926.601(b)(4) and 1926.602(a)(9), relate to back-up alarms, on trucks in construction, both of which are triggered when the operator's view is obstructed:1

Section 1926.601(b)(4) states:

§1926.601 Motor vehicles.
* * *
(b) General requirements,
* * *
(4) No employer shall use any motor vehicle equipment having an obstructed view to the rear unless:
(i) The vehicle has a reverse signal alarm audible above the surrounding noise level or:
(ii) The vehicle is backed up only when an observer signals that it is safe to do so.
(Emphasis added).

Section 1926.602(a)(9)(ii)2 states:

§1926.602 Material handling equipment.
* * *
(a) Earthmoving equipment; General.
* * *
(9) Audible alarms.
* * *
(ii) No employer shall permit earthmoving or compacting equipment which has an obstructed view to the rear to be used in reverse gear unless the equipment has in operation a reverse signal alarm distinguishable from the surrounding noise level or an employee signals that it is safe to do so.
(Emphasis added).

Where the back-up camera provides an "unobstructed view to the rear," that is, a clear view of the path the vehicle is to take, such that the driver can see if anyone is in that path or about to enter the danger area of that path, the requirement for an audible alarm or observer is not applicable. Here, the camera system provides the operator with a clear view to the rear and, thus, this back-up alarm requirement is not triggered.

Question #2: When operating a truck in reverse, is an employer that uses a radar/doppler or such motion sensing system in the rear of a truck - which warns both the driver and employees working within the vicinity of the vehicle whenever the truck is in reverse - in compliance with 29 CFR 1926 Subpart O?

Answer: #2: As stated above both §1926.601(b)(4) and §1926.602(a)(9)(ii) require employers operating trucks in reverse, with an obstructed view, to use a reverse signal alarm. As prior OSHA letters have explained, these standards provide employers with flexibility to use technology to meet this requirement. So long as the radar/doppler that you use provides adequate warning to workers in the path of the truck and to workers walking towards the path of the truck in time to avoid contact, you will be in compliance with this particular OSHA requirement.3

If you need additional information, please contact us by fax at: U.S. Department of Labor, OSHA, Directorate of Construction, Office of Construction Standards and Guidance, fax # 202-693-1689. You can also contact us by mail at the above office, Room N3468, 200 Constitution Avenue, N.W., Washington, D.C. 20210, although there will be a delay in our receiving correspondence by mail.


Richard E. Fairfax, Acting Director
Directorate of Construction

1 These provisions were promulgated in 1971.   [back to text]

2 OSHA assumes that the "truck" you refer to may constitute an "off-highway truck," as referenced in §1926.602(a)(1), thus triggering this provision.   [back to text]

3See Letter to Ms. Sue Nunn, Requirements for back-up alarms on construction (Nov. 3, 1998); Letter to Mr. Richard Holmes, Equipment reverse signal alarms must be audible above surrounding noise level (May 27,2004); Letter to "name withheld," Alternatives to common back-up alarms on construction motor vehicles; use of other effective technology or observers/signal persons (Sept. 27, 2004). OSHA letters are available on the agency's website at http://www.osha.gov.  [back to text]