The
Brisbane River has created a barrier to some road transport routes. In total there are
nine road bridges and one road tunnel, mostly concentrated in the inner city area. This has intensified the need for transport routes to focus on the inner city. One more cross-river tunnel is planned (East–West Link) as part of the
TransApex plan. Brisbane's road system was planned around large, spacious suburban areas. Dense suburbs now rely on several main road corridors that split through and between these areas and provide the only link to the CBD and other areas of Brisbane.
Logan Road,
Moggill Road,
Old Cleveland Road and
Gympie Road are but a few of these multi-lane corridors that come out of the CBD and snake through the suburbs. Bypasses such as the
Inner City Bypass,
Airport Link and
Clem Jones Tunnel are intended to help to circulate traffic away from the inner-city areas and main roads via limited-access roads above the ground, and tunnels below that have higher speed limits and exits to particular suburbs. Existing high speed cross-suburban motorways such as the
Western Freeway,
Centenary Motorway,
Pacific Motorway and
Gateway Motorway provide alternative routes to main roads and connect up to main highways and other arterial roads. The TransApex plan tunnels,
Airport Link tunnel and
Clem Jones Tunnel,
Legacy Way tunnel and East-West Link tunnel are designed to link all the various motorways in Brisbane together. Only East-West link is yet to commence planning or construction. In total, the twisting
Brisbane River is crossed by nine road bridges, one road tunnel, three railway bridges, three dedicated cyclist/pedestrian bridges and one dedicated bus/cycle/pedestrian bridge. Route signage is achieved by means of a system of
Metroads, consisting of the most important arterial roads in metropolitan Brisbane including most motorways, and less important
State Routes; however, in recent years, the Metroads are being superseded by an alphanumeric numbering system. Multiple freeways connect Brisbane to other cities, including the
Pacific Motorway, the
Bruce Highway and the
Ipswich Motorway, all of which are part of the
National Highway System. Brisbane is approximately away from
Sydney, the closest major capital city. An upgrade to Brisbane's traffic lights system began in April 2011. The old system was called
Brisbane Linked Intersection Signal System (BLISS) and required a controller to trigger traffic lights to relieve
congestion. The new system called
Sydney Coordinated Adaptive Traffic System (SCATS) is used in every other Australian capital city and is expected to cost much less to maintain. All 850 sets of Brisbane City Council signal boxes require upgrades. The north-west of the city lacks a major roadway. A Brisbane City Council investigation revealed the northside’s urban routes were not designed for the traffic volumes they were experiencing in 2020. Without the development of the North West Transport Corridor rapid population growth north of the city generates traffic congestion and is expected to lead to overcrowding on buses. ==Motorways==