Transport - general

Jul 16, 2014

The bridge: does it have to carry cars to be successful?

A new car-free bridge in Brisbane shows that strategically selected investment in bus, bicycle and walk infrastructure can have a huge effect on how people travel and where they choose to live

Alan Davies — Editor of The Urbanist

Alan Davies

Editor of The Urbanist

Mode split cars vs active modes (bus, bicycle, walk) for travel to University of Qld by staff and students (source: Charles-Edwards et al)

The main campus of the University of Queensland (UQ) in suburban St Lucia is enclosed on three sides by the Brisbane River. It provides an outstanding setting for arguably Australia’s prettiest university, but it significantly increases road travel times from the city centre and cuts the university off from Brisbane’s extensive southern suburbs.

Students and staff consequently mostly live north of the river, often at a considerable distance as the suburbs around the university are expensive. Until recently, those who lived to the south relied on small cross-river ferries or took a long detour by car or public transport to the nearest river crossings in the CBD (to the east) or Indooroopilly (to the west).

All that changed in 2006 with the opening of the Eleanor Schonell “green” bridge, which dramatically cut travel times from the south and to a lesser extent from the north. It’s known as the “green” bridge because cars can’t use it; it’s solely for “active” modes of transport i.e. buses, bicycles and pedestrians.

Fortunately, a number of academics from the School of Geography and Planning at UQ recognised construction of the bridge provided an opportunity to evaluate a ‘natural experiment’. They undertook a before-and-after study, looking at how the bridge affected student and staff decisions on travel and residential location.

Elin Charles-Edwards, Martin Bell and Jonathan Corcoran will publish their findings next month in the journal Urban Policy and Research (Greening the commute: Assessing the impact of the Eleanor Schonell “Green” bridge on travel to the University of Queensland, Australia). Gated, unfortunately.

They found the bridge had a dramatic impact on how members of the UQ community travelled to the St Lucia campus. In 2002, prior to construction, 39% of all students arrived on campus by car; however by 2011, after the bridge was built, the proportion plunged to 22%. For staff, the share of trips by car fell from 70% to 50% (see exhibit).

There was a corresponding big increase in the use of active modes over the period. The mode share of buses in particular jumped spectacularly; in the case of students from 27% to 53%. The increase for staff was even more remarkable; from 10% to 23%.

The key force driving these changes was improved access to the metropolitan bus network. The bridge lowered trip times by bus from the CBD and “opened up” new residential areas south of the river.

Students and staff took advantage of the improvement in accessibility. The proportion of all students living within a 10-minute bus journey of campus increased from 34% to 44% between 2003 and 2012; the proportion of staff increased from 21% to 37%.

The travel time to the university by bus from inner southern suburbs like Annerley and Wollongabba halved. The researchers say (1):

Prior to the construction of the bridge the campus was accessible from just seven Brisbane suburbs in under 10 minutes, only one of which (Chelmer) was south of the river. This increased to 17 suburbs south of the river (27 suburbs in total) following the opening of the bridge in 2006.

The number of students living in southern suburbs like Rocklea, Sunnybank and Cannon Hill increased markedly. However traditional student areas in the northern suburbs like Toowong and Auchenflower suffered losses; although their accessibility didn’t change because of the bridge, they now had to compete with “new” more affordable southern suburbs. (2)

The headline message from the Charles-Edwards et al study is that provision of good public transport infrastructure can lead to an extraordinarily large change in mode share. It’s also a striking example of how public transport infrastructure influences where people and activities choose to locate.

Further, US transport consultant, Jarrett Walker, says it shows that it’s not just rail that can shape the pattern “of real estate demand”; so can bus infrastructure (Brisbane: a city transformed by a bus link).

There are a couple of other important lessons from this project for public transport infrastructure planning.

One is that the success of public transport at UQ can’t be readily extrapolated to all other situations; this is to some degree a special case. UQ is a huge travel generator and it’s almost completely encircled by a wide river separating it from very desirable destinations a mere 200 metres away. This barrier wasn’t breached until 2006. As Jarrett Walker points out, “the issue here was classic chokepoint geography”. (3)

The other lesson is that the high mode share won by public transport at UQ is in large measure because cars got no benefit from the bridge. Had the new bridge also catered for them, it’s likely the change in mode share would’ve been very different. It reinforces the point that it’s rarely enough just to provide good infrastructure for active modes; a key requirement for significantly increasing their mode share is making cars less competitive.

The Eleanor Schonell “green” bridge shows that public transport can win spectacularly if it’s approached strategically. That’s a positive and valuable message; but whether it’s road, rail or bus, not all investments in transport infrastructure make good sense e.g. Melbourne’s proposed East West Link motorway and Doncaster rail projects. (4)


  1. I don’t think the travel times are meant to be taken literally; what matters is the relativities.
  2. It’s not possible to say definitively that all the changes between 2002/03 and 2011/12 were due solely to the bridge. There were other factors in play; for example, buses might’ve become more attractive anyway due to progressive improvements in the bus system and cars might have been rendered less competitive because of increasing congestion.
  3. There are a number of highly developed localities in Australia separated by major barriers, especially water, from most of their neighbours e.g. Balmain, New Farm.
  4. The researchers say the mode share of both cycling and walking increased for staff over the period but fell a little for students (Table 3 in the paper). I don’t get that; unless staff out-number students, Table 2 in the paper seems to indicate the student mode share also increased.
Cycling isochrones for the UQ St Lucia Campus before and after the opening of the Eleanor Schonell Bridge (source: Charles-Edwards et al)


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6 thoughts on “The bridge: does it have to carry cars to be successful?

  1. Socrates

    Michael James

    Dudley is correct. Anna Bligh did oppose the different bridge proposed as part of the Bris-Tram project in the late 90s, when in opposition. It was a very stupid position for her to take. As a result, in the subsequent Brisbane Light Rail project proposed under the Beatty Labor government (Bligh was a minister) the bridge link was removed. THis killed the economics of the project and it was eventually scrapped.

  2. Raaraa


    I’d like to know who the project manager for this bridge is, and can they be hired to manage more government projects??


    Tramway extension……?

  3. michael r james

    #2 Dudley Horscroft at 10:05 am

    Re Anna Bligh, I think that is complete nonsense. It was Labor who built the bridge*. You are almost certainly getting confused about the various arguments between Labor state government and Campbell Newman’s city council who 1. wanted it to be a car bridge and 2. having given up on cars still wanted to run buses thru the campus. Their own blue blood voters in St Lucia have always blocked such schemes, in this instance I agree with them; for the same reason an agreement with the UQ was reached that the buses were not allowed to operate thru-routes, which may have made sense from a bus network point of view but, as AD said, this is an exceptionally nice campus and running a freeway thru would be awful. So buses just do a turnaround on the UQ side (and there is no actual road connection to MacGregor Drive (that circumnavigates the university along the river).

    However, not described here, is what really transformed it. Namely that it is part of a busway network. Although it was not built immediately, after a few years the tunnel carrying the busway was built connecting up with the SE Busway provided a super-efficient route that connected up with both the city and southern suburbs completely independent of roads. Of course this meant that the buses were largely** immune to the road congestion–and right in front of the bridge is a bad point on Annerley road. The busway tunnel goes under it.

    Incidentally another point about this rather graceful bridge (cable-stayed) is that it cost only $55m. It’s not a small bridge. For some reason it escaped the crazy cost inflation that has afflicted all other major infrastructure projects. For example the replacement of the pedestrian walkway + bikeway along ≈300m of the NewFarm riverfront (replacing the bit washed out by the 2011 flood) is to cost $100m! Lunacy. The Go Between car bridge built shortly after Schonell has cost >$300m!
    *It is the Qld state government who funds and builds the busways but it is the BCC who runs the buses on them.
    **I say “largely” because the busway system has become a victim of its own success, with terrible bus congestion at several pinch points at peak hours. The service to UQ runs from the city centre and so is subject to this problem as it (like almost all buses) must cross the Vic bridge before entering the segregated busway that runs along the side of the SE Expressway.
    I have been an advocate of converting the busway to lightrail, and use buses only as a feeder system at the big bus stations (instead they run huge numbers of buses, often empty in one direction or both, all the way from outer Brisbane into the centre, hence the bus congestion). The carrying capacity would be much greater with no congestion. Apparently the engineers ensured the busway would be relatively easy to convert to lightrail.
    Further, IMO if it was lightrail running across the E Schonell bridge I reckon those St Lucia residents might eventually concede it going beyond the UQ into their suburb and back to Toowong (by which it would remove all buses from these roads). Needless to say nothing like this will be contemplated by Premier Newman. The first thing (literally, within 24 hours of being elected) he did as Mayor was to remove the dedicated buslane that ran along Coronation Drive from the city to the UQ and gave it back to cars.

  4. Alan Davies

    Dudley Horscroft #2:

    The Brisbane River is so serpentine that, while West End is north of the campus, it’s on the south side of the river and the university is on the north side.

    Re note 4 that explanation initially occurred to me too, but one of the tables in the paper suggests walking and cycling increased in both absolute and relative terms. I’ve written to the authors seeking clarification.

    Don’t know about light rail to Doncaster, but it would have to make more sense than heavy rail.

  5. Dudley Horscroft

    I recall that the tram extension over the Green Bridge was virulently opposed by Anna Bligh who was the member for, I think, West End, on the north shore opposite the University. Rather a disgraceful opposition as the tramway wold have benefitted her area as well as the Uni. Still, it is good to see that it is well used.

    Re your note 4, it is quite feasible that mode share for walking and cycling for students fell, as well as their mode share for cars, if the bus share increased very substantially which, on the graph you show, it probably did.

    Re your final comments, there never has been any good sense in the East West Motorway tunnel, but there is more sense in the Doncaster Rail line. Even better would be the Doncaster Light Rail, as proposed by the MMTB way back – made good sense then, makes better sense now.

  6. hk

    Is anyone in a position to be able to quantify population level health impacts from this change in infrastructure investment?

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