How to deal with alternating one-way traffic

At roadworks with alternating one-way traffic, vehicles are controlled by traffic lights, marshals or priority signs. Wait your turn before the narrowing, and do not enter if the queue ahead will prevent you from clearing it.

Know who has priority

Alternating one-way traffic allows vehicles to use a stretch that can normally carry traffic in only one direction at a time, such as a narrowing caused by roadworks. The order may be controlled by temporary traffic lights, marshals or signs giving priority to one direction. Approach slowly and identify the control method in good time; do not rely only on the fact that you cannot see a vehicle ahead.

If the light is red, stop at the line or before the point indicated. If there is a marshal, follow their signals and do not set off until they tell you to. Where signs require you to give way or give priority in alternating one-way traffic, follow the instruction and check that the stretch is clear. A vehicle approaching from the opposite direction may be hidden by a bend or the roadworks.

Do not enter the narrowing if the queue ahead is stationary and you risk getting stuck inside it. Even with a green light or a favourable signal, complete the manoeuvre without obstructing oncoming traffic or work vehicles. Leave room for workers and obey temporary speed limits; debris, heavy machinery and an uneven surface may require an even lower speed.

• Slow down before the roadworks and look for lights, a marshal or priority signs.
• Stop at the line when the red light or marshal requires you to.
• Do not enter until the stretch is clear and you can exit it completely.
• Obey temporary limits, cones and instructions from road workers.

If the controls are unclear

If the traffic light is out or flashing, do not assume that you may go. Follow any signs and proceed with particular care, giving way under the applicable rules and allowing anyone already in the stretch to pass. If a marshal is present, wait for a clear instruction. Avoid reversing inside the narrowing: if you cannot proceed, stop somewhere safe and wait for instructions.

At night, check that cones and temporary lights are visible and that there are no people or equipment in the carriageway. If the route is closed, follow the diversion instead of going round the barriers.

You can review temporary signs and priority rules with Quiz Patente Ufficiale: study chapters, timed quizzes and review of mistakes.