Bike Law | BikesBeSafe

Bicycles May Use Full Lane (R4-11)

The Bicycles May Use Full Lane sign, also referred to as BMUFL or R4-11, first officially specified in Chapter 9B of the 2009 Manual on Uniform Traffic Control Devices, is a traffic sign used in the United States to:

designate roads with lanes that are too narrow to be safely shared side-by-side by a bicycle and another vehicle to indicate that bicyclists may occupy the full lane to discourage unsafe within-lane passing
encourage bicyclists to use the full lane to discourage unsafe within-lane passing
encourage motorists to change lanes to pass bicyclists
warn motorists that bicyclists may be using the full lane

The sign consists of a graphic image of a bicycle, followed by the words, "May Use Full Lane".

REQUIREMENT FOR LIGHTS AND REFLECTORS: § 42-4-221. Bicycle and personal mobility device equipment: 1 No other provision of this part 2 and no provision of part 3 of this article shall apply to a bicycle, electrical assisted bicycle, or EPAMD or to equipment for use on a bicycle, electrical assisted bicycle, or EPAMD except those provisions in this article made specifically applicable to such a vehicle.Every bicycle, electrical assisted bicycle, or EPAMD in use at the times described in section 42-4-204 shall be equipped with a lamp on the front emitting a white light visible from a distance of at least five hundred feet to the front.Every bicycle, electrical assisted bicycle, or EPAMD shall be equipped with a red reflector of a type approved by the department, which shall be visible for six hundred feet to the rear when directly in front of lawful lower beams of head lamps on a motor vehicle.

§ 42-4-111. Powers of local authorities

This article shall not be deemed to prevent local authorities, with respect to streets and highways under their jurisdiction and within the reasonable exercise of the police power, except those streets and highways that are parts of the state highway system that are subject to section 43-2-135, C.R.S., from:
(h) Regulating the operation of bicycles or electrical assisted bicycles and requiring the registration and licensing of same, including the requirement of a registration fee, consistent with the provisions of this article;