Box junction

King William Street from The Monument - geograph.org.uk - 1974829

Chile road sign RPO-17

Box junction is a traffic control measure designed to prevent congestion and gridlock at junctions. The most recognizable feature of a box junction is the criss-cross yellow lines painted on the road surface. These lines indicate an area that vehicles are not permitted to enter unless their exit from the junction is clear, or when making a permitted turn. The concept was first introduced in the United Kingdom in 1967 and has since been adopted in various forms in other countries.

Overview

A box junction works by prohibiting vehicles from entering the box area unless their exit path is clear of obstructions. This rule aims to keep the junction open for traffic crossing in other directions, thereby reducing the chance of gridlock. The only exception to this rule is when a driver is making a turn that is allowed and has to wait within the box due to oncoming traffic or other immediate obstructions.

Legal Basis

In the United Kingdom, the operation of box junctions is governed by the Traffic Signs Regulations and General Directions 2016 (TSRGD). Drivers who enter a box junction and are unable to clear it can be fined, with enforcement typically carried out by local authorities using CCTV cameras.

Design and Usage

The design of a box junction includes yellow hatched lines forming a square or rectangle. The size of the box can vary depending on the size of the junction and the volume of traffic. Box junctions are commonly found at busy intersections, particularly where two or more roads intersect and there is a significant amount of crossing traffic.

Effectiveness and Criticism

Box junctions are generally effective at keeping traffic flowing through busy intersections. However, they can be a source of confusion for drivers unfamiliar with the rule or the area. Critics argue that in some cases, box junctions can lead to increased congestion on the approaches to the junction, as drivers wait to ensure their exit path is clear before entering the box.

Global Use

While the concept originated in the UK, similar traffic control measures have been adopted in other countries, often with local variations. For example, in Singapore and parts of Malaysia, box junctions are also used, with enforcement and rules that closely mirror those in the UK.

See Also

• Traffic congestion
• Intersection (road)
• Traffic enforcement camera