VDOT Updates Vehicle Warning Light Policy: What Contractors Need to Know

VDOT issued a memorandum on June 25, 2026, announcing two changes to vehicle warning light policy that affect contractors operating snowplows and truck-mounted attenuators (TMAs) on VDOT roads.

Change #1: Nighttime Dimming Now Explicitly Allowed

Effective immediately, VDOT has clarified that the existing minimum visibility requirement (½ mile at night) does not preclude dimming warning lights at night. Operators of non-VDOT work vehicles, including contractor vehicles, are authorized and encouraged to dim warning lights at night to the extent practicable, aiming for roughly 1,200 candelas to reduce glare for workers and drivers. All other VWAPM requirements — flash rate and 360-degree visibility – remain in effect.

Change #2: Green/Amber Lights Now Permitted on Snowplows and TMAs

Effective July 1, 2026, new state legislation (Chapter 498) authorizes alternating green/amber warning lights on snowplows and TMAs, a bill promoted by VTCA. Key points for contractors:

• Snowplows and TMAs may now use amber and/or alternating green/amber warning lights.
• All other work vehicles (including shadow vehicles without attenuators) must continue using amber only.
• If used, green/amber lights must be equal parts green and amber, housed together or side-by-side, and synchronized if multiple units are on one vehicle.
• Snowplows may only show green while actively plowing or pre-treating; TMAs may only show green when the attenuator cushion is deployed.
• White/clear warning lights remain prohibited.

Contractors with questions about equipment compliance should consult the full memorandum, contact VTCA staff, or contact VDOT Traffic Engineering for guidance as the Department updates the VWAPM to reflect these changes.