The direction of automobile traffic alternates every five minutes, controlled by a traffic light at each end of the tunnel. The bicycle lanes, one for each direction, are located on either side of the reversible lane; buttons on either side of the tunnel trigger flashing signs alerting drivers entering the tunnel to the presence of cyclists. Entire roadway formerly reversed The Southern Expressway in Adelaide, South Australia, was the world's longest exclusively one-way reversible road. It opened in 1997 and eventually traversed though the city's southern suburbs, until its duplication to carry two-way traffic completed in 2014. It changed direction to carry peak hour traffic to the city centre in the morning and away from the city in the evening. On weekends, the directions were reversed. One lane formerly reversed Motorway M7 in Hungary from 1972 until the completion of the second carriageway in 1975. The existing carriageway between Törökbálint and Zamárdi normally operated with one lane in each direction, but carried traffic towards Budapest only on Sunday afternoons. Alfords Point Bridge in Australia from 1973 till bridge duplication in 2008. The center lane was reversible. After 2008, a 300-metre reversible center lane still remained on Alfords Point Road over Henry Lawson Drive, approximately 500 meters north of this duplicated bridge. Escalators In shopping centres and metro stations there may be an odd number of escalators, with one or more escalators running in different directions in different time of a day. See also Contraflow lane Contraflow lane reversal Single-track road Stop-gap References Road infrastructure Road traffic management Types of roads Repurposing Articles containing video clips