Box junction
From Free net encyclopedia
A box junction is a traffic control measure designed to prevent gridlock at busy road junctions. The surface of the junction is marked with a criss-cross grid of diagonal painted lines (or rather only two lines crossing each other in the box junction, as it is used widely in Singapore) and vehicles may not enter the area so marked unless their exit from the junction is clear (or, if turning, to await a gap in the oncoming traffic flow). In the United Kingdom, drivers may enter the box and wait when they want to turn right, and are only stopped from doing so by oncoming traffic, or by other vehicles waiting to turn right. [1]
Similar yellow boxes may be painted on other areas of roadway (such as the exits from emergency vehicle depots) which must be kept free of queuing traffic.
Box junctions are currently used in the United Kingdom (where they were invented), New York City, Hong Kong, Singapore, the Republic of Ireland, Malta, South Africa, major cities in Brazil, and Toronto.
The state of California has an ordinance which bans gridlocking (entering the intersection without being able to clear it, and thus blocking traffic from other directions) at all intersections. No special signs, markings, or other traffic control devices are used to indicate this.
Boxes are also used in Perth Western Australia at rail crossings and some intersections.