GOING UNDERGROUND? - Why turning to pedestrian under and overpasses in the CBD would be a retrograde step.   

Underpass 1.jpg

Greater Hobart is suffering from growing pains. Or at least, that is the increasing opinion of the average car user and voter as they attempt to deal with the traffic congestion along Davey and Macquarie streets, particularly at certain times of the day. These two principal highways through the city often fail to handle the rising number of private vehicles at certain times of the day; they are also seen as major barriers to pedestrian movement, separating the CBD from Sullivans Cove.

Recent speculative hotel development proposals have suggested they could alleviate the issue by contributing towards the construction of footbridges over Davey and Macquarie streets. They suggest the footbridges would be a community benefit associated with the granting approval for their projects. This adds to existing queries of how (and perhaps more tellingly, who is) to manage the future of the two highways. In response, the City of Hobart Council commissioned a report into the feasibility of introducing pedestrian under or overpasses to help link the city back to its Cove and alleviate disruptions to traffic flow.  

It is perhaps revealing that the current mindset solves the problem of traffic congestion by making  the pedestrian the culprit. So seeking solutions through infrastructure designed to remove pedestrians from the street should come as no surprise. Under and overpasses are well-established solutions that emerged in the 1940s when the ideology of traffic engineering placed the motorcar first, giving them specific rights of way that prioritized and separated them from the pedestrian. The urban street has been re-designed and engineered for the sole purpose of accommodating the flow of traffic with pedestrian movement micro-managed to fit around this vision. The under and overpass represents the ultimate solution for this ideology by effectively removing the pedestrian from the street altogether and placing them on an entirely different level to the traffic.

The 60's Segregated City of Tomorrow  

The 60's Segregated City of Tomorrow  

Todays Tokyo Bus Station Skybridge.  

Todays Tokyo Bus Station Skybridge. 

Highway engineering identifies three primary advantages to such infrastructure: improvements in safety; improvements in the walking experience; and relief to traffic congestion. Yet studies into the relative success of under and overpasses based on the these criteria are at best inconclusive, and more often found to be negative. When coupled with emerging evidence of additional negative impacts upon the social and economic life of the city, such expensive (estimated between $8-to-15 million per crossing) and often invasive pieces of infrastructure should be questioned as representing a rigid and out-dated ideological design approach that has not served city life well.

Let’s look at a primary argument for under and overpasses: improved road safety.  One of the fundamental problems is that their design and placement often fails to understand how pedestrians actually use space. Notwithstanding the designer’s desire to guide the user along safe and secure routes, it is no surprise to learn that a number of global studies have found that a majority of adults will actively avoid using either under or overpasses if a level crossing exists anywhere within close proximity. As early as the 1970s, it was reported at the joint Australian Road Research Board (ARRB) and Department of Transport Pedestrian Conference, that in a survey of 12 such crossings in Victoria over an eight-year period, more than 55% of adults preferred to ignore them, choosing instead to cross at ground level.

Various reasons were suggested in the report as to why this might be the case. These ranged from familiar perceptions, such as sensations of confinement; the potential presence of undesirable people; the prevalence of litter and graffiti; the inability to orientate oneself; and susceptibility to wind and flooding. In studying how people actually move through spaces, urban designers have identified that the principal reason is that the average pedestrian will simply choose the most direct route where possible. This is especially true if the alternative is seen as unattractive or adding unnecessary distance, exertion or complexity. We’ve all seen images of ‘Desire Lines’ or ‘Desire Paths’, and they adequately demonstrate that when faced with the choice of extra distance, rise and falls in levels, often including steps, people just prefer to wait for a gap in traffic and cross at existing level crossing points or junctions.

Designer Intention vs Desire Lines. 

Designer Intention vs Desire Lines. 

Desire Line directly under footbridge.  

Desire Line directly under footbridge. 

Early morning and three Pedestrians cross Burnett Street directly above its Underpass. 

Early morning and three Pedestrians cross Burnett Street directly above its Underpass. 

In the past, highway engineers have attempted to minimise such crossings with fencing that physically blocks access to the road; however, even when such fencing is used over long stretches of the highway, pedestrians will still attempt to leap over them, or walk up to the end of the fence and set off into the road, dodging the traffic as they go. The ARRB and Transport Commission of Victoria recently reported that, unfortunately, such mid-block pedestrian crossings have been found to account for 25% of all pedestrian accidents involving fatalities or serious injury on Victorian roads; the highest of all the identified causes. So while such crossings may provide safe passage for many pedestrians, they may actually result in accidents occurring in locations where previously they had not occurred at all, therefore, negating the intended benefit and demonstrating a clear design failure.

Fencing to direct Pedestrians.

Fencing to direct Pedestrians.

Circumnavigating Barriers. 

Circumnavigating Barriers. 

Such a clear discrepancy between the theory of how people should behave and how they actually do is measurable. What is less easy to measure is the number of pedestrian trips that don’t occur as a result of such infrastructure. Taking the next stated criteria: improvement to the walking experience; it has been shown that most walking trips are relatively short with pedestrians being acutely sensitive to the distance involved and the quality of space and conditions through which they move. If the trip is considered to represent too much of an inconvenience, people will not walk. This is especially true where multiples of inconveniences are adjudged to occur.  Therefore even minor detours away from the most direct route, such as not crossing at junctions, or if the walking experience is degraded by the poor quality of the immediate environment, are enough to dissuade the casual pedestrian.

Complexity and effort create Mental Barriers

Complexity and effort create Mental Barriers

Poor Streetscapes leads to decline in retail.

Poor Streetscapes leads to decline in retail.

As reported in Dr Jake Desyllas influential 'The Cost of Bad Street Design" the uninterrupted decline in walking in the UK since the 1960s has been especially acute along streets that have been redesigned to accommodate higher levels of traffic capacity through the use of barriers and separation infrastructure such as under and overpasses. And research by the University of London shows that just as good urban design adds to the economic, social and environmental value of the city, bad design has the opposite effect. Thus, reduced numbers in pedestrians in turn leads to a decline in retail along those streets; when the pedestrian leaves, so does business.  Similarly, a recent study of pedestrian movements in Moscow undertaken by Gehl Architects found that in a city known for its many pedestrian underpasses, a disproportionate number of certain members of society were absent from street life: the elderly; families with prams; people suffering from mobility issues and children. Whilst it is statistically true that these members of society are often viewed in lower numbers in city centres, recorded numbers were so low it was concluded that rather than avoid using the underpasses, these members of society simply no longer even attempted to walk into the centre of the city.

Those with Mobility issues in Moscow.

Those with Mobility issues in Moscow.

Townscape as obstacle course.

Townscape as obstacle course.

Clearly, using ramps instead of steps to under and overpasses can improve the relative attractiveness to a degree. Nonetheless, even modern designed crossings, with their elongated ramps and gradients suffer from consistent under-use and whilst compliance with Australian mobility codes may be achievable (by significantly increasing the length of ramps), they represent a significant hurdle to those with mobility issues as opposed to crossing at ground level. Their unpopularity increases the risk of pedestrians no longer making those small walks across town, which are the lifeblood of the city. Rather than act as physical connectors, they instead act as mental barriers to connectivity. When that impact is disproportionately experienced by certain members of society, denying equitable access equates to denying full participation in urban life resulting in a city no longer for everyone.

Turning then to the last criteria: improvement to congestion. It is perhaps reasonable to suggest that given the mounting pressure from commuters to improve traffic delays, issues surrounding improved pedestrian safety and connectivity were not the foremost in the mind of those that commissioned the report. Of course, whether the introduction of under and overpasses to Macquarie and Davey streets would indeed reduce congestion, it is clear from countless studies that without exception, improvement in the capacity of streets to carry traffic only ever leads to greater levels of traffic using these streets. Any relief is always temporary.

Notwithstanding the above, what would such infrastructure do to improve congestion within the centre of Hobart? Certainly it would reduce the waiting time for traffic moving through this space if the number or duration of red lights along these streets were reduced. However, these surface pedestrian crossings are located on the junctions of the feeder Murray, Elizabeth, Argyle and Harrington streets. In its design guide “Designing Good Quality Pedestrian Facilities”, the Queensland Government comments that even when crossings are removed, pedestrians will still attempt to cross roads that have interrupted traffic movements. Under and overpasses are therefore only considered appropriate where traffic flows are uninterrupted and then ‘only as a last resort’. To achieve such an uninterrupted traffic flow would therefore require these feeder streets to be closed off entirely to turning traffic, effectively turning Macquarie and Davey into urban motorways. Should that not occur, pedestrians would still attempt to cross at these points (even when fencing is employed) and the actual reduction in time awaiting for red lights to turn to green would be marginal at best. Essentially, the average time it takes for a pedestrian to cross the street,  is approximately 20 seconds.

It is difficult to envisage such a radical alteration to the highway layout of central Hobart and the reaction of car users is unlikely to be supportive of such changes.Yet for even marginal improvements to levels of congestion along these streets to occur through the introduction of pedestrian under and overpasses, such additional alterations and expenditure would appear unavoidable. The potential flow on problems of congestion to other parts of Hobart’s road network would appear to be significant however and would effectively merely relocate and exasperating the problem to the cities secondary road network.

Of course, all of these potential failures in the central stated criteria for the provision of such expensive infrastructure are only part of the perceived problems and costs associated which these proposed engineering solutions. Walking is essentially the most flexible method of movement through the city. One can change direction, speed or destination at will and offers opportunities for interaction and social engagement in a way that no other method of movement can. To walk is to experience and take part in a multi-layer forum of social activities.

The social life of the City. City Hall Square, Copenhagen.

The social life of the City. City Hall Square, Copenhagen.

Hobart's own Social Life, alive and well when given the chance.

Hobart's own Social Life, alive and well when given the chance.

In the UK, the Commission for Architecture and the Built Environment (CABE) was established by the Government in 1999 to promote high standards in the design of new buildings and the spaces between them. In its report to the Select Committee examining walking in towns and cities it states:

CABE believes that walkers should be given primacy in the urban environment and seen as being at the apex of the transport hierarchy; walking is still the main means of movement on towns and cities and the planning our streets should reflect that. In particular, phasing of pedestrian crossings needs to take account of walkers’ needs and pedestrians must be able to move around at surface level rather than being forced into dank underpasses or up steps onto footbridges. Clear targets should be introduced for the removal of major pedestrian underpasses and their replacement with surface crossings.

Typical Footbridge, St. Margaret's, London. 

Typical Footbridge, St. Margaret's, London. 

Typical Underpass.

Typical Underpass.

Under and overpasses make a clear statement as to who or what is important and valued in the life of the city, and who is not. The separation of pedestrian from traffic merely further entrenches the hierarchy which places the car above the pedestrian and other methods of transport, and further absolves the car user of responsibility to the congestion we all produce. Macquarie and Davey would increasingly appear as urban motorways and be treated as such, creating ever worse levels of traffic and the environment they create whilst driving a wedge between the city and the cove much as the post war Westway in London,  the Expressway in New York and the Cahill Expressway across and above Circular Quay in Sydney cleaved apart communities.

Under the Westway, London.

Under the Westway, London.

Under the Expressway, New York.

Under the Expressway, New York.

Another cost difficult to price, but seemingly highly valued, is the potential impact upon the streetscape and townscape of the city’s historic core. It is difficult to imagine several examples of such large and invasive pieces of infrastructure and associated barriers being comfortably slotted into a townscape that contains one of the highest concentrations of Heritage-listed buildings and places in the entire country. The social cost associated with the degradation of Hobart’s historic core would reflect the disastrous impacts such work had upon cities like Birmingham and Bristol in the UK, which suffered huge damage as historic areas were cleared to produce segregated traffic and pedestrian townscapes. It is only in retrospect that these cities have realised the damaging impact of such development, demolishing the raised walkways, filling in underpasses and re-introducing attractive pedestrian friendly ‘streets’ and sequences of vibrant spaces as a vital component of the social city. In return, the people have flocked back to the city centre, with Birmingham City Council estimating that footfall in places has increased by 50%.

Hobart's Historic Core.

Hobart's Historic Core.

Birmingham City Centre re-born.  

Birmingham City Centre re-born.  

Last are the potential health implications of such development. Reductions in the number and duration of walks are one of the key contributors to the rise in obesity in the developed world. It is estimated that 14,000 preventable deaths occur annually in Australia primarily due to a lack of physical activity. As walking is one of the basic elements of physical health, the degrading of the everyday walking experience in the urban streets of our cities can have serious health and cost implications. Limiting the potential to create ‘living’ streets that create a wealth of impressions and cater for a myriad of modes of travel in favour of just one decreases the health of the city, physically as well as spiritually.

Award winning High Street Kensington, London

Award winning High Street Kensington, London

Oxford Circus, London before... 

Oxford Circus, London before... 

Wide level crossings, City Hall Sq. Copenhagen.   

Wide level crossings, City Hall Sq. Copenhagen.  

..and after removal of barriers and new widened crossings. 

..and after removal of barriers and new widened crossings. 

Of course, advocates for under and overpasses would suggest that something needs to be done to deal with the ever growing problem of congestion on these two streets. Seeking solutions that sit outside of the standard highway engineering toolbox are likely to be difficult to implement, with the onus on those suggesting such alternative methods lying outside well established guidelines to accept liability and responsibility. Nobody has ever been criticised for sticking to the guidebook. However, there are examples of streetscapes designed to allow both high levels of traffic and pedestrian numbers to co-exist without segregation. High Street Kensington and Oxford Circus in London and City Hall Square in Copenhagen all deal with significantly higher levels of traffic and pedestrian movements but are designed specifically to create a pleasant and flexible pedestrian environment by removing barriers and acknowledging pedestrian desire lines. However, perhaps the most successful and well known example is that of the Pavement to Plaza program undertaken by New York City between 2007 and 2014. As reported in the cities Department of Transport Study 'Pedestrians:Broadway', the various improvements to the public realm through increased public spaces, widening of pavements and creation of pedestrian orientated ground crossings in one of the busiest urban areas in the world has actually led to less congestion, shorter travel times, a 35% reduction in traffic related injuries to pedestrians and an 15% increase in pedestrian movements through the space. This in turn has revitalised the local economy with an enormous 180 percent increase in area retail rents. It is now estimated that an incredible 400,000 people walk through the space each day. 

These case studies have shown that adopting integrated approaches to building readily understandable, navigable pedestrian friendly streets can create attractive spaces which respond to local context and still carry heavily levels of traffic. Through the use of techniques like ‘gateway’ markers, higher levels of planting, widened footpaths, painted and raised crossings that carry pedestrian surfaces over the road and the removal of barriers can shift the burden of extra awareness onto the driver with positive safety results. Reducing speed limits to under 50km an hour (or better 30 km an hour) and re-thinking the one-way system approach currently adopted can have a significant impact on improving pedestrian safety at a fraction of the cost to the rate payer or the social cost of the city.

Coloured wide crossing, Times Square, New York.

Coloured wide crossing, Times Square, New York.

Impression of potential similar crossing, Hobart. 

Impression of potential similar crossing, Hobart. 

Perhaps the single most pertinent statistic however was recently quoted by Dr James McIntosh at the ‘Moving Hobart’ traffic forum held at the Town Hall. Simply put, it is estimated that of all the motorised journeys that take place in the greater Hobart area on any one day, 95% of those are undertaken in private vehicles. This is a figure that is simply unsustainable. Throughout the developed world, car sharing programs walk to work/school schemes, improvements in walking and bike facilities are just some of the simple but effective methods of reducing the number of private vehicle journeys even before any discussion is made concerning improvements to public transport. These schemes can often be implemented at a fraction of the cost of expensive pieces of infrastructure. Unfortunately, they often suffer from operating ‘under the radar’. Unless successfully publicised, they may not have the visual immediacy of an over or underpass, especially in a political world where it is often more important to be seen to be doing something than necessarily the right thing. The high numbers of private transport points to an unpleasant reality; however, for the most part, we all share some blame for the current state of affairs. Shifting the blame to the pedestrian would be entirely wrong and counterproductive, especially if adopting infrastructure solutions based on a failed and increasingly abandoned philosophy of Highway Engineering. This would lead the city truly down an unfortunate dead end.


Nick Booth of nbd-space is an Urban Designer based in Hobart. His work includes acting as the Urban Design consultant and concept co-designer of the Collins Court re-development in Hobart's CBD.