Advance Warning Signs

All work zone signing (ground or truck mounted) shall conform to the NMUTCD and NYS Supplement. Special conditions or emergencies may require additional signing. Refer to the MUTCD and the NYS Supplement for guidance on the proper location, message, spacing, sequence, mounting height and size of signs used for traffic control.

Rigid and flexible “roll-up” signs may be used for mobile, short duration and short-term stationary work. Rigid signs must be mounted at least 5 feet above grade (7 feet where there are pedestrians or parked cars) for visibility and to avoid windshield penetration if they are impacted. Flexible signs must be mounted at least one foot above grade. Mesh signs shall not be used. Use retro reflectorized rigid signs for night work because they present a flat, uniform reflective surface.

Sign stands/posts meeting NCHRP 350 crash testing are acceptable until they can be feasibly replaced by units meeting MASH crash testing standard. Ex: breakaway posts and hinges. TMIAs

All signs should face at approximately right angles to on-coming traffic and be as close to vertical as possible to avoid reflecting sun glare into the driver’s eye.

In mobile and short duration work zones, signs may be mounted on vehicles. Orange flags shall be mounted on warning signs to enhance their visibility according to the appropriate Typical Application.

Signs shall be maintained, clean and with the legend fully intact. They shall remain in place only when needed. Signs which do not reflect actual conditions promote driver disobedience of all signs and therefore should be covered, removed or turned away so they are not visible to traffic in any travel lane. Sign covers must be opaque and cover the sign face completely. Partially visible signs may divert attention away from traffic and other devices.

If unneeded signs are to be stored at roadside, try to store them out of the clear zone or as far from traffic as practical. If stored close to traffic, lay the signs flat and fold up the legs of the sign supports.

Where operations are performed in stages, only use those devices that apply to the conditions present during the stage in progress. Signs set up over a long distance should be periodically checked.

• Install work zone advance-warning signs pursuant to Typical Applications whenever the work results in a changed condition which may require a higher level of driver caution. For work which obstructs traffic, a 3-sign series is typical. The first sign is a general warning sign to get the motorist’s attention. The second sign warns of the specific condition and the third sign advises the driver of any action to be taken.
• Location of advance warning signs should consider exiting and entering traffic. Advance posting distances indicated in the MUTCD and WZTCM are starting points and should be adjusted as appropriate for site specific conditions. Avoid starting a warning sign series upstream from a major exit or intersection, except when it is desirable to divert traffic off the route at that point or where the intersection is within 1000 feet of the work site.
• Warning signs must be located to provide adequate visibility distance to drivers; not blocked by foliage, roadway features, or other signs and traffic control devices; and not located where glare from light sources behind the sign may reduce visibility. Actual distance from a warning sign to the condition should be close to the stated distance on the sign, but accuracy should not be at the expense of sign visibility.
• Signs must be adequately spaced to provide time for the driver to read each one. Sign spacing varies with the type of highway and the prevailing speeds and is specified in the MUTCD and WZTCM. See Advance Warning Sign Spacing Table on the next page for details.
• In urban conditions, advance warning sign spacings may be adjusted in order to accommodate side streets and driveways