The Cities we want: toward sustainable urban transport

Author Dr Russell Tregonning takes a self administered dose of cycling
Author Dr Russell Tregonning takes a self administered dose of cycling

This one-day seminar held on Monday 2 February was part of the Department of Public Health, Otago University, Wellington Medical School’s Summer School,.

The implications for cycling and cyclists from the main presentations in the morning session are contained in this blog. In the afternoon, Pecha Cucha presentations from various speakers, and a panel discussion were held.

The Keynote speaker, Prof Harry Rutter started the conference by video-streaming from Oxford, UK. Harry is a public health doctor and chair of the NICE/walking and cycling group for the National Institute of Health (among other qualifications). His talk was titled ‘Climate Change, Obesity and Active Travel’.

Harry pointed to the increasingly hard evidence for the health benefits of cycling accumulating in the medical literature. Studies suggest that there is a clear dose-response relationship between the amount of cycling and health outcomes. With increasing amounts of daily cycling, fitness improvement increases, and the risk of all-cause mortality, cardio-vascular disease (heart attacks and strokes–CVDs) and colon cancer morbidity decrease: the incidence of over-weight and obesity also decreases.

Shifting from car to bicycle is good for health. A 2011 study showed the health benefits of cycling are 11 times larger than the risks relative to car-driving for subjects shifting mode of transport. It also showed that societal benefits are even larger due to modest reduction in air pollution emissions and decreased traffic accidents. Recent papers from the BMJ and Lancet also showed the potential of a shift from oil-based to food-based active transport to provide important health benefits for car-users and wider society. The Lancet article stated “The greatest potential for health gain is by improving the walking environment and supporting the most energy-efficient form of transport—the bicycle.”

Harry also pointed to the research showing the ‘safety in numbers’ effect for those involved in active transport. A study of relative risk to walkers and cyclists from Californian cities reports the dramatic reduction of risk as the percentage of journey-to-work share increases from less than 5% upwards.

There have been massive recent studies on the Global Burden of Disease (GBD), funded by Bill Gates, with health statistics gathered from all over the world. Harry pointed out that the GBD statistics show that millions are killed or injured on the roads globally, but these numbers are dwarfed by deaths and morbidity from cardio-vascular diseases(CVDs.) The most effective antidote to these CVDs is regular exercise. Evidence also shows that the main intervention for health seems to be shifting residence to Netherlands or Denmark! (These countries show a very high proportion of their population commuting by bicycle).

Peter Bass of TERNZ described the methods and aims of a study which is being developed in Mangere Central, Auckland called ‘Future Streets: TeAra Mua’. This case-control study starting in early 2015 is to be supported by a number of universities, councils and ACC, among others, with funding from MBIE. The aim is to measure the effects of retrofitting existing streets to make them safer and healthier. A lower socio-economic city area currently dominated by the car has been chosen as it is known that poorer suburbs have increased crash rates and inactivity-related diseases like CVDs and obesity.

Design principles of the study include reducing and making more consistent traffic speeds, with schools and the Mangere Central mall being priority destinations for safe walking and cycling . An arterial separated bike network will be an important infrastructure improvement. Data collected will include vehicle, cycle and pedestrian movements and crashes, and door-to- door surveys of residents’ physical activity, travel patterns and social networks. Guiding principles of construction include the introduction of ‘self-explaining roads’ where motorists are encouraged to slow down because of the infrastructure design eg by narrowing the roads with cycleway construction and other measures. It is known that big, wide roads encourage speeding despite traditional slow-down signs. Peter emphasized that increasing road safety is predominantly a health issue—it not only reduces crashes, but reaps the major health benefits of safer walking and cycling. Analysis of data is timed for 2016.

Michael Keall, from the Dept. of Public Health, Wellington Medical School, described ‘the ACTIVE study–increasing cycling and walking in NZ cities’. ACTIVE is the acronym for ‘Activating Communities To Improve Vitality and Equality’. The design of the study was quasi-experimental with two intervention cities (Hastings and New Plymouth) matched to two control cities (Masterton and Whanganui). It sought to evaluate the impact of the creation of new cycling infrastructure (local government initiated and central government-funded) designed to make active travel easy and attractive.

Michael’s began by emphasizing that important health benefits of exercise arise only from its regularity: such habitual exercise can be obtained by routine commuting by cycling or walking, with the latter being part of most public transport trips also. He indicated that cars are becoming more dominant, accompanied by lower levels of active travel in many countries, including NZ. He noted the very low percentage of commuters who walk and cycle to work in New Zealand compared internationally (only the US and Australia are worse). Data also showed the strong correlation of reduced active travel and obesity (obesity rates in New Zealand are third highest globally, just behind the US and Mexico).

Analysis of household travel behavior data was obtained from the NZ Household Travel Survey home interviews from three consecutive years (2011-2013). In a first-stage evaluation, the rates of active transport in the treatment group were static compared with the control cities where the rates continued to decrease. The study’s conclusions were
that “the Model Communities programme can be
regarded as successful in arresting a strong trend towards ever-decreasing levels of active travel”.

[originally posted by Russell]