TrafficInfraTech Magazine Linking People Places & Progress
All public transport trips and many car and motorcycle trips include an element of walking. For a Transportation Expert public transport trip, this could include walking to an initial bus stop, an interchange between bus, train or metro, within a metro station and at the end of a trip. Even for private motorised trips, walking is often required to or from a parking lot. When walking is inconvenient or unsafe, people have more incentive to use private cars or taxis, especially if this avoids crossing busy roads without safe and convenient crossings, or simply to reduce walking the distances. In principle this is taken account of in transport planning: within multi-modal transport demand forecasting and planning models, it is usual for walk to be assigned a greater cost per unit of time than waiting (‘in-vehicle time’) when the various elements of a journey are combined into ‘generalised cost’ or ‘generalised time’ (the difference between these terms being determined by whether monetary and time costs are summed as equivalent/perceived units of currency or units of time). Many cities would claim to provide pedestrian infrastructure such as footbridges. However, in some cases these are anything but convenient to use just like in the opening photograph where the high elevation of the footbridge acts to dissuade many pedestrians from using it, thus risking their own safety.
It is often said that within modern urban environments, especially in rapidly developing cities, there are many conflicting demands for space that some form of trade-offs are always going to be necessary. This is illustrated in the photograph on the next page which was taken in Kunming, China. Here cars, taxis, buses, cycles and pedestrians are all accommodated. Pedestrians are able to cross wide roads at-grade, but to cross the road away from major junctions requires the use of steep, narrow footbridges.
In the same photograph, the sheer weight of numbers seems to force the use of footbridges. However, in other parts of China, it is not uncommon to see either security guards or policemen attempting to enforce the use of inconvenient footbridges. Similarly, in many cities in the Gulf at-grade pedestrian crossings are removed in favour of very high footbridges, which then necessitate the stationing of a police officer to enforce the use of the crossing; exceptions are then made for the mobility impaired who are then expected to cross the busy road which now has no signalised control to facilitate crossing by even able-bodied pedestrians.
The above situations raise the obvious questions – why is walking so often overlooked? Why is it inadequately, or even inappropriately, addressed? Whilst the precise reasons – and their relative importance – can vary between cities, three broad reasons can be identified, which may overlap to an extent:
– Inappropriate data and tools
– Institutional weakness and/or lack of co-ordination
– Aspirational bias
Inappropriate Data and Tools
Walk-only trips and the walk legs of other trips are often under-emphasised or even ignored in data collection exercises — either because respondents forget them or because they are forgotten when surveys are scoped. So such data are not collected. The author was recently interviewed for the latest Travel Characteristics Survey in Hong Kong; and amazingly, walk trips which were reported to the interviewer were not recorded in the daily trip diary! So walking cannot be considered in subsequent analysis.
City-level planning tends to rely on strategic transport models which are geared to evaluate longer distance trips. Due to time, budgetary, data and computing constraints, such transport models simplify transport networks; this is not necessarily an issue for estimating the potential demand for inter-district travel. However, people are often assumed to have barrier-free access to public transport, often ignoring realities such as uncrossable roads.Since the barriers to walking are often ignored, the forecasts of public transport patronage get affected – they become inflated. This risks downstream financial problems for scheme payback. The outturn impacts on traffic congestion too get affected as they prove to be less than what was envisaged by planners and decision makers. All this might foster an environment in which walking per se is largely ignored.
Other modern approaches, such as the use of Geographic Information Systems (GIS), often suffer from problems similar to those of strategic transport models, with roads treated as links and junctions as nodes, which are often assumed to be convenient for pedestrians to cross.
It should be noted that the data collection requirements for an approach which would have accurately reflected barriers to pedestrian movements would be highly onerous, even in mature, developed cities. So an ideal solution is perhaps untenable. Nevertheless, the implications of simplifications in planning tools should be borne in mind. For example, transit planners often use ‘walk in distances’ defined as the distance a public transport customer is likely to be willing to walk to, or from, a bus stop or metro station. However, such walk distances as estimated from transport models or GISs are likely to ignore barriers such as crossing a busy road to get back from a bus stop on the other side of the road. The photograph on the previous page illustrates this: the lady in the photograph has alighted from a bus on a side-road (itself congested); she is about to ascend a concrete incline, after which she has to cross a dual carriageway (without pedestrian crossing facilities) to get to the side of the road she wants to.
