thumb|[[Concrete barrier]]
A roadblock is a temporary installation set up to control or block traffic along a road. The reasons for one could be:
- Roadworks
- Temporary road closure during special events
- Police chase
- Robbery
- Sobriety checkpoint
- Protests
In peaceful circumstances, they are usually installed by the police or road transport authorities; they are also commonly employed during wars and are usually staffed by heavily armed soldiers in that case. During protests and riots, both police and demonstrators sometimes use roadblocks.
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File:Roadblock in Palestine.jpg|Roadblock in the West Bank
File:Barykada.jpg|Polish barricade during the Warsaw Uprising (1944)
File:Roadblocks.jpg|Roadblock during roadworks at Hisingen, Sweden, 2013
File:London November 23 2018 (19) Extinction Rebellion Protest Tower Hill.jpg|'Swarming roadblocks' Extinction Rebellion, (UK) (23 November 2018).
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See also
- Road traffic control
- Barricade
- Boom barrier
- Braess's paradox
- Illinois v. Lidster
- Safety barrier
- Traffic break