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Melbourne Transport |
Common Urban Myths About TransportMyth:
Freeways relieve traffic congestion
Fact:
They may provide some short-term relief, but within a short time the extra
road capacity generates more traffic than there was before. In the long
term freeways just allow congestion to grow further: they don't reduce it.
Road planners often promise that freeway building will relieve traffic congestion, especially on the arterial roads that freeways bypass. But the promised relief, if it arrives at all, is usually only temporary. Official acknowledgement that freeways do not relieve traffic congestion is found in numerous places. For example, in April 2005 VicRoads told a planning panel examining new road construction in central Geelong that the $400 million Geelong Bypass will not, as popularly supposed, relieve traffic congestion on major roads like Latrobe Terrace. Supporting the proposed removal of a heritage overlay to allow a left turn slip lane to be built, VicRoads submitted that
Similarly, a 2004 report by traffic consultants Parsons Brinkerhoff for the City of Whitehorse confirmed that building the Mitcham-Frankston Freeway (MFF) will do nothing to relieve traffic congestion at the intersection of Springvale Road and Whitehorse Road.
But the best known official debunking of this myth is the report of Britain's Standing Advisory Committee on Trunk Road Assessment (SACTRA) in 1994. This states:
The first reason freeways fail to relieve congestion is that freeway traffic still has to go somewhere before and after it uses the freeway. Prior to the construction of CityLink, VicRoads published figures showing that many roads allegedly 'relieved' by CityLink would actually be carrying more traffic after City Link opened than before. Some of this would be through toll avoidance: thus VicRoads predicted that traffic in Mount Alexander Road would more than double, a prediction that has since come to pass. But they also predicted an 80 per cent increase in traffic in Gatehouse Street, a 65 per cent increase in Peel Street, and even an increase on Punt Road at the freeway junction. These increases had nothing to do with people avoiding tolls, but rather the effect of drivers changing routes once CityLink was in place. The second reason is that new roads create new traffic. Thus, even the Vicroads figures above have actually proved to be too low. Indeed, VicRoads and other road lobby consultants have consistently underestimated the traffic consequences of new roads in their traffic studies, such as for the Mulgrave-South Eastern Freeway link in the 1980s and the Eastern Freeway extension in the 1990s. This is because their computer models assume that improved roads don't generate any additional traffic. Even as recently as 2006, the Bracks Government touted a consultants' report claiming the EastLink tollway would bring $15 billion of economic benefits to Victoria. Yet the report's authors admit that the figure was obtained by assuming not one extra car trip would be made as a result of the road being built.
The evidence, both statistical and anecdotal, shows otherwise. Though new roads do temporarily reduce traffic flows on parallel routes, this relief is almost completely wiped out after a few years. Take for example the link between the Mulgrave and South Eastern Freeways built in 1988:
Source: ARRB Transport Research, Report No. 299
While all that new traffic was flocking on to the Monash Freeway and the
roads parallel to it, the road lobby was building CityLink, whose marketing
material proclaimed it to be a lasting solution to Melbourne's traffic
problems such as those caused by the 'dead-ending' of the Monash Freeway
at the city end. Cold reality has proved otherwise: barely five years
after CityLink opened in late 2000, the Monash Freeway was called Meanwhile, the parallel King Street route through the CBD is still classified as a major freight route by the road engineers at Melbourne City Council, and this is given as a reason why more priority can't be given to trams on the cross streets. Needless to say, things would be very different if CityLink had really taken all the trucks off King Street, the way it was supposed to do. But while car and truck trips have shifted from King Street to CityLink, just as many entirely new car and truck trips have appeared to take their place. The story is the same in Sydney. In 1992 the Sydney Harbour Tunnel opened amid promises that it would fix traffic congestion on the Harbour Bridge forever. The truth is quite different, as the traffic counts show:
After remaining steady over the five-year period from 1987 to 1991, traffic levels both on the bridge and in the tunnel increased throughout the 1990s as Sydney swapped a congested bridge for a congested bridge-and-tunnel. The final cost of the tunnel was $738 million in 1992 dollars; a high price to pay for just a few years of reduced congestion. Traffic levels in the tunnel have now reached 80,000 per day, meaning that its effect has been not to reduce congestion but instead to increase the number of cars crossing the harbour by nearly 30 per cent - despite no similar increase in the size of the central Sydney workforce. In the 1950s, American transport planners used to claim that roads respond to traffic, but don't cause it. This is nonsense, of course. Road engineers used to be the only business people who thought that if they improved their produce, they wouldn't get more customers! VicRoads planners are still stuck in the 1950s, denying that road building will produce additional traffic.
Outside the cut-and-thrust of political lobbying, the new traffic created by new roads is tacitly acknowledged in official circles. The Australian Institution of Engineers, the professional body representing road builders, says in its policy material:
And very occasionally, the new traffic 'induced' by new or bigger roads will be acknowledged by the government, sometimes even in the same breath as they call for even more new or bigger roads in order to reduce traffic congestion. Thus, the following statements are juxtaposed on the same page of a State Government brochure, apparently without irony:
Meanwhile, the Eastlink tollway is likely to increase rather than reduce traffic congestion in the City of Manningham, according to the road planners:
Be prepared for the same road planners to 'solve' this problem with another freeway - just as Eastlink was supposed to 'solve' congestion problems in the eastern suburbs. Proponents of the westward extension of the Eastern Freeway have likewise tried to have their cake and eat it too, citing as a benefit
In other words: yes, building Eastlink will increase congestion, but don't worry, this new freeway will reduce it again! One can also find figures in Vicroads' own annual report demonstrating that building freeways hasn't reduced the level of congestion. In fact, the overall level of congestion (as measured by the average delay to traffic) has remained steady over at least the last decade, with reductions in congestion in some locations evenly balanced by increases in congestion elsewhere. What is even more clear is that freeway-building has increased the amount of car travel by 13 per cent over 10 years, faster than the increase in Victoria's population (even when offset by a slight decrease in 2006 due to higher petrol prices).
Source: VicRoads, Annual Report 2006, page 57. The final verdict - that freeways in the long term increase traffic congestion, rather than reducing it - came in 1994 with the release of the SACTRA report mentioned above. The British Department of Transport's own expert team concluded that new roads can and do generate traffic.
The latest research confirms that this effect works the other way as well: closing roads, or reducing road capacity through traffic calming, can actually cause traffic to disappear!
The car works best as a form of travel when few people use it: increasing traffic leads to congestion, making driving less attractive. By contrast, public transport service improves as patronage increases, as frequent services and express runs become more viable. Where public transport and roads are in competition, as in Melbourne, expanding road capacity is a two-way loser. It attracts additional traffic, making road conditions worse, and reduces public transport patronage, making public transport less attractive as well! Conversely, improving public transport can make life easier for both public transport and road users. Vancouver in Canada has built no freeways for decades, and has invested in public transport instead. In the last decade, average travel times to work have reduced as a result. This paradox is widely recognised by transport planners overseas, and even has an official name: the Downs-Thompson Paradox. One doesn't have to look hard to find examples of this principle in action. Case Study No.1:The extension of the Eastern Freeway to Springvale Road, built in the mid-1990s, parallels and competes with the Lilydale/Belgrave rail line. Currently, the rail line is Melbourne's busiest, carrying around 15,000 passengers in the morning peak hour, just under half its capacity. Although much wider than the rail line, the Eastern Freeway before it was extended carried only about half this volume (8,000 passengers) but even they strained the road's capacity, with traffic banked up at the City end of the freeway for three or four kilometres. Now that the freeway has been extended, the traffic jams have grown to twice as long, and commuters who drive into the city from Templestowe regularly complain about the longer delays due to increased traffic! (The further extension of this freeway to Frankston is predicted to dump an extra 28,000 cars a day at the City end - many of which would be escapees from neglected public transport services.) Case Study No.2:Within weeks of the South Eastern Arterial link opening in 1988, 20% of peak passengers on the Glen Waverley train line shifted to the freeway. Services on the rail line were reduced as a result: in 1987 there were seven peak period expresses on the Glen Waverley line; ten years later there were only two. This has pushed still more passengers onto the freeway, setting up a vicious spiral. Since there are many more rail passengers than freeway users, improvements to the freeway will be cancelled out even if a minority of rail passengers shift their mode of travel. The overall result is that, after the expenditure of hundreds of millions of dollars and the destruction of areas of great scenic beauty, we have worse conditions for both road users and public transport passengers! Case Study No.3:With the Environment Effects Statement for the Scoresby Freeway in 1997, we finally got official confirmation in Melbourne that public transport can be a more effective treatment for congestion than new freeways. The government's consultants wrote:
In other words, the same savings in road user costs would result from increasing public transport mode share by just 1.15 per cent, as from building the freeway. (In the latter case the savings would of course be only short-term, as traffic levels would soon build up until there is just as much congestion as before.) As soon as it was realised that it might damage the case for the Scoresby Freeway, this finding was buried in an obscure supplement to the EES, and no more detailed investigation of any public transport alternative to the freeway ever took place. Case Study No.4:In 2005 the road lobby began agitating for a new freeway parallel to the West Gate Bridge, pointing out that between 1994 and 2004 peak-hour travel time over the bridge had more than doubled, from 11 to 25 minutes. But it turns out that this 240% increase in travel time has resulted from only an 18% increase in traffic volume - from 17,600 cars to 21,800 between 6am and 9am. Public transport in the western and northern suburbs is truly woeful, with trains running only every 20 minutes in peak hour and buses even less often; meanwhile construction of the $630 million Western Ring Road has fed induced traffic onto the bridge. If public transport were improved tomorrow so as to attract one in six journeys away from car travel, traffic on the West Gate Bridge would revert to its relatively free-flowing conditions of 1994. On the other hand, building a second West Gate Bridge is likely to only give us two congested bridges in place of one. ConclusionIn the heyday of freeway building in the 1950s, the well-known architect and urbanist Lewis Mumford warned that trying to cure traffic congestion with more road capacity was like trying to cure obesity by loosening your belt. The result of too much belt-loosening can be seen throughout the USA, where 'suburban gridlock' is endemic. We are not yet at such an advanced stage of urban decay; we can avoid it entirely if we want to.
© 2007 Public Transport Users Association Inc. (PTUA), Victoria, Australia. ABN 83 801 487 611. Last modified: 29 January 2008
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