Boom barrier
Encyclopedia
A boom barrier is a bar, or pole pivoted in such a way as to allow the boom to block vehicular access through a controlled point. Typically the tip of a boom gate rises in a vertical arc to a near vertical position. Boom gates are often counterweight
ed, so the pole is easily tipped. Boom gates are often paired either end to end, or offset appropriately to block traffic in both directions. Some boom gates also have a second arm, which pivots on links that allow the second arm to hang 300 to 400 mm below the upper arm when it descends into the horizontal position, in order to increase approach visibility.
Boom gates are typically found at level (rail) crossings
, drawbridges
, parking facilities
, checkpoints and entrances to restricted areas. They are also the usual method for controlling passage through toll booth
s, and can also be found on some freeway entrance ramps which are automatically controlled to drop in order to restrict traffic in the event of accident cleanup or road closures without the need to dispatch road workers or law enforcement to use a vehicle to block the way.
Some boom gates are automatic and powered, others are manually operated. Manual gates are sometimes hung in the manner of a normal gate (i.e. hinge
d horizontally).
In some places, boom gates are installed across suburban streets as a traffic calming
measure, preventing through traffic, while allowing authorised
vehicle
s such as emergency service
s and bus
es to take advantage of the shorter and more direct route.
Counterweight
A counterweight is an equivalent counterbalancing weight that balances a load.-Uses:A counterweight is often used in traction lifts , cranes and funfair rides...
ed, so the pole is easily tipped. Boom gates are often paired either end to end, or offset appropriately to block traffic in both directions. Some boom gates also have a second arm, which pivots on links that allow the second arm to hang 300 to 400 mm below the upper arm when it descends into the horizontal position, in order to increase approach visibility.
Boom gates are typically found at level (rail) crossings
Level crossing
A level crossing occurs where a railway line is intersected by a road or path onone level, without recourse to a bridge or tunnel. It is a type of at-grade intersection. The term also applies when a light rail line with separate right-of-way or reserved track crosses a road in the same fashion...
, drawbridges
Bascule bridge
A bascule bridge is a moveable bridge with a counterweight that continuously balances the span, or "leaf," throughout the entire upward swing in providing clearance for boat traffic....
, parking facilities
Parking
Parking is the act of stopping a vehicle and leaving it unoccupied for more than a brief time. Parking on one or both sides of a road is commonly permitted, though often with restrictions...
, checkpoints and entrances to restricted areas. They are also the usual method for controlling passage through toll booth
Toll house
A tollhouse or toll house is a building with accommodation for a toll collector, beside a tollgate on a toll road or canal. Many tollhouses were built by turnpike trusts in England, Wales and Scotland during the 18th and early 19th centuries...
s, and can also be found on some freeway entrance ramps which are automatically controlled to drop in order to restrict traffic in the event of accident cleanup or road closures without the need to dispatch road workers or law enforcement to use a vehicle to block the way.
Some boom gates are automatic and powered, others are manually operated. Manual gates are sometimes hung in the manner of a normal gate (i.e. hinge
Hinge
A hinge is a type of bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about a fixed axis of rotation. Hinges may be made of flexible material or of moving components...
d horizontally).
In some places, boom gates are installed across suburban streets as a traffic calming
Traffic calming
Traffic calming is intended to slow or reduce motor-vehicle traffic in order to improve the living conditions for residents as well as to improve safety for pedestrians and cyclists. Urban planners and traffic engineers have many strategies for traffic calming...
measure, preventing through traffic, while allowing authorised
Authorization
Authorization is the function of specifying access rights to resources, which is related to information security and computer security in general and to access control in particular. More formally, "to authorize" is to define access policy...
vehicle
Vehicle
A vehicle is a device that is designed or used to transport people or cargo. Most often vehicles are manufactured, such as bicycles, cars, motorcycles, trains, ships, boats, and aircraft....
s such as emergency service
Emergency service
Emergency services are organizations which ensure public safety and health by addressing different emergencies. Some agencies exist solely for addressing certain types of emergencies whilst others deal with ad hoc emergencies as part of their normal responsibilities...
s and bus
Bus
A bus is a road vehicle designed to carry passengers. Buses can have a capacity as high as 300 passengers. The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are...
es to take advantage of the shorter and more direct route.
See also
- Four-quadrant gateFour-quadrant gateA four-quadrant gate is a type of boom barrier gate protecting a grade crossing.It has a gate mechanism on both sides of the tracks for both directions of automotive traffic...
- Automatic full barriersAutomatic full barriersAutomatic full barriers are a set of four half-barriers closing a road at a railway level crossing.Typically the barriers on the approach side to the crossing are lowered first with those on the exit side following shortly after. The sequence timing is set to allow enough time for a vehicle or...
- Toll collection technology