Social media argument has been frantic this month in China, where former China Central Television anchor and investigative reporter Chai Jing raised mass public awareness of the health problems from smog when her online video documentary went ‘viral’. Citing former health minister Chen Zhu, the video claimed that an estimated half a million people died prematurely in China every year because of air pollution. Critics claimed there was no scientific evidence to support the video's link between the rising number of cases of heart disease and air pollution.
Meanwhile in Hong Kong, I read with interest the recent Report from the Transport Advisory Committee on road traffic congestion in Hong Kong. The Report focuses, unsurprisingly, on the economic impacts to the city of increased car journey times, but it does take a shot at the fact that “traffic congestion will continue to erode the environment, sustainability, quality of life and competitiveness of the city and that immediate action is warranted”..
The pollution problems caused by urban traffic worldwide have in fact been well documented for many years. My recent trip to UK was able to remind me of how reducing urban traffic was breathing new life into towns and cities.
Currently 38,000 new cars are taking to China’s streets each day, fuelled by the need to keep the economic boom at full tilt. According to the State Statistical Bureau, the country had merely 0.5 million cars on the road in 1990, but the number exploded to 43.22 million privately-owned cars by 2011. It is estimated that annual sales are forecast to reach 22 million in 2020; roughly 60,000 vehicles per day. The growing middle classes believe they must have their own private vehicle as an expression of their newly acquired affluence.
Trends overseas however continue to show a movement away from city road building and upgrading projects, to that of streets dedicated to wider public use solutions such as dedicated bus and cycle lanes, shared streets and pedestrianisation schemes. Not only are new roads rarely being built, but existing streets in urban areas are being torn up, narrowed, greened and redefined.
In the US, car sales have decreased year on year since peaking in 1986 at almost 11.5 million. 25 years on, annual sales are roughly half that number and the trend can be expected to continue despite the ever growing population.
Awareness of the health issues from emissions are of particular concern in congested city street conditions, not to mention the psychological stress resulting from noise and safety issues. Emissions include particulates from diesel engines, NOx, volatile organic compounds, carbon monoxide and benzene. A World Health Organization study found that diesel fumes directly cause an increase in lung cancer.
It's not just exhaust fumes that are likely hurting us; brake dust, tire fragments and even tiny bits of road can get into the air and these make up a similar proportion of the airborne particulate matter (PM) resulting from vehicle use as exhaust emissions.
A recent study estimated that approximately 64,000 people in the United States die prematurely from heart and lung disease every year due to particulate air pollution -- more people than die each year in car accidents. Among children, air pollutants are associated with increased acute respiratory illness, increased incidence of respiratory symptoms and infections, episodes of longer duration, and lowered lung function.
Asthma, the most common chronic disorder of childhood, is on the rise in the United States and in other industrialized nations. During the 1980s, the prevalence of childhood asthma increased nearly 40 percent. Many different factors have been associated with asthma, but several studies have linked particulate air pollution with exacerbations of asthma in children afflicted with the disease.
Young children generally spend more time low to the ground by virtue of both their shorter stature and the nature of their typical physical activity. Children, therefore, experience greater exposure to pollutants emitted close to the ground, such as automobile exhaust and high-density pollutants brought downward by gravity. In addition, when the sources of air pollutants such as automobiles are close to playgrounds and other areas where children play, children and infants in strollers may be heavily exposed.
My recent visit to UK confirmed that removing traffic from the streets is showing major improvements to urban centres. London is now a different city since the introduction of congestion charging policy to its central area; one of the proposals mooted in the Hong Kong Study. Buses are flowing freely, public bikes are for hire on street corners and cafes are sprawling over pavements previously occupied by vehicles.
The charge, introduced in 2003, remains one of the largest charge zones in the world and aims to reduce congestion whilst raising funds for London's public transport system. During the first ten years since the introduction of the scheme, gross revenue reached about £2.6 billion through December 2013. From 2003 to 2013, about £1.2 billion (46%) of net revenue has been invested in public transport, road and bridge improvement and walking and cycling schemes. Of these, a total of £960 million (equal to RMB 9.08 billion) was invested on improvements to the bus network. An overall reduction of 11% in vehicle kilometres travelled has been recorded in London between 2000 and 2012.
Coupled with this, traffic speeds have been getting progressively slower over the past decade, particularly in central London. This has primarily resulted from interventions that have reduced the effective capacity of the road network in order to improve the urban environment, increase road safety and prioritise public transport, pedestrian and cycle traffic. 
Visiting historic Oxford, 100kms northwest of London, required leaving the car on the outskirts of the city in one of five large and well appointed car parks and taking a shuttle bus a short distance into the city centre on dedicated bus lanes. Out of the window I witnessed pavements being widened and dedicated bicycle lanes. Once inside the heart of the town, the central area is widely pedestrianised with high quality finishes and crowded with activity and business free from excessive vehicle emissions.
Permanent bus based park and ride schemes are most often found in the UK in historical towns and cities where the narrow streets mean traffic congestion hits hardest and streets cannot easily be widened.
Implementation of public transport park and ride bus services in the UK accelerated through the 1980s and 1990s, with schemes ranging in size from an allocated area with provision of less than 10 cars, to multiple dedicated sites catering in total for nearly 5,000 cars. Schemes predominantly serve a single town or smaller city, while rail based mode, where it exists, is the predominant implementation for the larger metropolitan areas. As of 2005 there were 92 park and ride sites across 40 locations in England.
The widespread availability and affordability of car travel has brought many benefits to society. Cars offer the freedom to travel to almost any destination, at whatever time, with passengers and luggage and minimal need to plan ahead. They have made it easier to keep in touch with friends and family and to reach a wider range of job opportunities.
But these freedoms have been obtained at a substantial price, and one that generally falls most heavily on the poorest and most vulnerable in society; those who are generally unable to benefit from private vehicle use themselves suffer from the effects of other peoples travel. The negative impacts include deaths, injuries and the threat of accidents that restrict others’ freedoms; air and noise pollution; community severance and the loss of social cohesion.
More car journeys have created congestion and produced a more hostile street environment. Walking and cycling in particular have become more dangerous and unpleasant as the number of vehicles on the roads has increased. Land use patterns have changed to reflect car use with shops and services moving to vehicle accessible areas. Society has become hard-wired to increasing levels of car dependency.
Research from the Institute of Transport Economics in Oslo suggests that the cost of community severance (the ‘barrier effect’ due to transport infrastructure such as busy roads) is even greater than the estimated cost of noise pollution and almost equal to the cost of air pollution.
The essential challenge for newly industrialising governments is to shirk traditional, urban transport solutions that are primarily focused on providing benefits to the individual, and to protect all of their citizens with frameworks and policies which strike a balance for the wider society and are equitable for both this and future generations.