It happens a lot - you're stuck in stop-and-go traffic and the cars in the other lane always seem to be going a little faster. Should you switch lanes?
No, according to safety experts at Tüv Thüringen, a technical inspection agency in Germany. Jumping lane doesn't save any time, the say.
What's more, many drivers become distracted in traffic jams and may notice too late you're switching lanes, which significantly increases the risk of rear-end collisions.
Changing lanes forces the drivers behind to brake again and again, and constantly crossing the emergency lane is also dangerous.
When you're stuck a traffic jam you should slow down and keep a little more distance from the vehicle in front, the experts recommend.
In normal conditions, half the speed in metres is the correct distance - so at 100 km/h, you should be at least 50 metres away from the car in front of you. Guide posts that are 50 metres apart can be used for orientation.
Even at low speeds or in stop-and-go traffic, there must be enough distance from the vehicle in front. Depending on your speed, you should keep a distance of around three car lengths in order to be able to react in time to a sudden stop.
Anyone arriving at the end of a traffic jam should switch on the hazard lights and brake carefully as possible.