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Traffic jamWorldwide

Learn traffic rules with clear explanations and visual examples in our illustrated book, designed to make studying simple and engaging.

Traffic signs
Traffic rules
Worldwide

96. Traffic jam

A traffic jam is a situation where traffic becomes heavily congested and vehicles move very slowly or stop for extended periods. Traffic jams are commonly caused by high traffic volumes, accidents, roadworks, lane closures or poor weather. Drivers should remain patient, keep a safe distance, avoid unnecessary lane changes and watch for motorcycles, emergency vehicles and sudden braking. Where lanes merge during congestion, local rules may require drivers to use a zipper-merging system.

Warning for traffic jam. (Geneva, Switzerland)
Wikimedia.org • Marc Mongenet • CC BY-SA
What is a traffic jam?

A traffic jam occurs when traffic becomes congested and vehicles move slowly or remain stationary because the road cannot accommodate the normal flow of traffic.

What causes traffic jams?

Common causes include heavy traffic, accidents, roadworks, lane closures, bottlenecks and poor weather.

How should you drive in a traffic jam?

Keep a safe distance, avoid sudden braking and unnecessary lane changes, and remain alert for changing traffic conditions and emergency vehicles.

Should you change lanes frequently in a traffic jam?

Usually not. Frequent lane changes can disrupt traffic flow and increase the risk of collisions. Change lanes only when necessary and safe.

What is zipper merging?

Zipper merging is a system where drivers use all available lanes until a lane ends or becomes blocked and then merge alternately into the remaining lane.

Should you leave space for emergency vehicles in a traffic jam?

Yes. Many countries require or recommend drivers to create space for emergency vehicles when traffic becomes congested or stationary.

1 Worldwide 2 Motorway 3 Expressway 4 Residential area 5 Built-up area 6 Zone 7 Speed limit 8 Minimum speed 9 Advisory speed 10 Footpath 11 Bike path 12 Shared-use path 13 Separated path 14 Pedestrian warning 15 Tunnel 16 Bridge 17 Cycling street 18 Pedestrian zone 19 Speed bump 20 Toll road 21 Customs 22 One-way traffic 23 Quay 24 Slope 25 Bus lane 26 Bus stop 27 Dead end 28 Stop sign 29 Give way 30 Roundabout 31 Priority road 32 Road narrowing 33 Priority over oncoming traffic 34 Give way to oncoming traffic 35 Pedestrian crossing 36 Railway crossing 37 Mandatory direction 38 Turn prohibition 39 School area 40 Overtaking 41 Crossing animals 42 Slippery road 43 Rockfall 44 Aircraft 45 Curve 46 Chevron 47 Wrong-way driving 48 Roadworks 49 Crosswind 50 Height limit 51 Width limit 52 Length limit 53 Weight limit 54 Radar speed sign 55 Selective barriers 56 Low-emission zone 57 Intersection direction sign 58 Priority at the next junction 59 Traffic lights 60 Traffic lights warning 61 Pedestrian lights 62 Road markings 63 All-way stop 64 Junction layout 65 Climbing lane 66 Bike box 67 Left-hand traffic 68 Speed feedback 69 Driving licence 70 Location marker 71 Road number 72 Countdown markers 73 Public toilet 74 Rest area 75 Traffic mirror 76 Emergency telephone 77 International border 78 Pedestrian underpass 79 Cycling route 80 End of restriction 81 Parking 82 No parking 83 No stopping 84 Parallel parking 85 Park and ride 86 Kiss and ride 87 Alternate-side parking 88 Parking meter 89 Parking disc 90 Disabled parking 91 Traffic management 92 Merging 93 Reversing 94 U-turn 95 Carpool 96 Traffic jam 97 Detour 98 Uncontrolled crossroad 99 Road surface 100 Advisory cycle lane ...