Slip lane

Illustration (left-hand traffic): the blue vehicle in the slip lane must give way to the green and red vehicles even though the latter is at a give way control.

A slip lane or slip road is a road traffic lane provided at an intersection to allow vehicles to turn at the intersection without actually entering it and interfering with through traffic. It is therefore not controlled by any traffic signals at that intersection. There are two types of slip lane - those where the lane continues into its own lane in the road which it turns into and those where the lane terminates at the point where it enters the road turned into.

Risks

Slip lanes are a dangerous design element, and therefore controversial in urban and suburban contexts - many cities are therefore actively removing them. Slip lanes may need to be removed if considerations such as pedestrian safety grow to a point where they over-ride the desire to facilitate free passage for cars.

To minimise risks of collision, slip lanes can be shaped to enter the traffic flow at a higher angle than the 45 degrees shown in the first sketch. Such lanes are called high entry angle slip lanes.

Australia

In Australia cars exiting a slip lane must give way to all other traffic even when that traffic is faced with a give-way or other traffic controls.

See also

• Interchange
• Advanced stop line
• Continuous-flow intersection
• Hook turn
• Quadrant roadway intersection
• Seagull intersection
• Superstreet
• Texas T
• Texas U-turn
• Turnaround