The Embassy has submitted a response to a NICE consultation on draft guidelines, 'Air pollution: outdoor air quality and health'. Our suggestions to a number of points in the NICE consultation (in italics) are below.
1.1.1 Take air quality issues into account in the Local Plan for new developments. For example: Provide an infrastructure to support low- and zero-emission travel. This could include cycling and walking routes
Our suggestion - Change 'could' for 'should' or 'must', in reference to cycling and walking.
1.4.2 Where speed reduction is needed to reduce road danger and injuries (see NICE's guideline on preventing road injuries), take account of the potential adverse impact on air pollution. Consider 20-mph zones in residential areas characterised by stop–go traffic where this will reduce accelerations and decelerations. Where physical measures are needed to reduce speed, such as humps and bumps, ensure they are designed to minimise sharp decelerations and consequent accelerations.
Attempting to tackle pollution on residential streets by tinkering with street features misses the most obvious and sensible way of dealing with the problem – by removing extraneous motor traffic.
Crucially, 20mph zones should correspond to areas of low motor traffic (under 2000 vehicles per day), areas carefully designed to limit the motor traffic using the streets in those zones to access-only, by means of point closures, or a system of carefully arranged one-way streets.
In other words, there should be no extraneous motor traffic in 20mph zones – no motor traffic that is travelling through them to go somewhere else. In and of itself, this should greatly reduce vehicular emissions on these kinds of street. There should be very little 'stop-go' traffic in these areas, altogether – only residents and other vehicular access.
In addition, street features like humps will often be an integral element of safe design for walking and cycling in these 20mph zones – for instance, ensuring clearer priority for walking at side roads, as well as ensuring that vehicle speeds remain low. Problems of pollution in these areas should not be tackled by adapting or removing these features, but by tackling the problem at source – by removing extraneous motor traffic, and therefore creating safer, calmer and more attractive street environments.
1.5.1 Avoid siting cycle routes on highly polluted roads. Ideally use off-road routes or quiet streets.
Useful cycle networks will essentially have to cover every single road and street in an urban area. Failing to provide cycling infrastructure on main roads, even if they are polluted, will create gaps in that network that will make journeys by cycle difficult or impossible. (By analogy, imagine a walking network that did not include any footways on main roads, and how effective that might be at enabling people to make useful journeys on foot).
Cycling infrastructure should not merely consist of 'routes' that can be sited on backstreets as an alternative to main roads; it must consist of a network that goes everywhere. Main roads will almost always form important parts of that network, as well as being destinations in their own right. Failing to include main roads in cycle networks will not enable modal shift to cycling, consequently maintaining the status quo of a large proportion of short urban trips made by the most polluting modes.
1.5.2 Where busy roads are used consider - providing as much space as possible between the cyclist and motorised vehicles; using dense foliage to screen cyclists from motor vehicles, without reducing street ventilation so that air pollution can disperse.
While we agree in principle that cycling should, on grounds of comfort, safety and attractiveness, be separated from motor traffic as much as is reasonably possible, context is extremely important. Route directness should not be sacrificed; nor should cycleways or cyclepaths be designed in a way that isolates them from the social functions of the road they run along.
Dense, screening foliage may also present safety issues, particularly at side road junctions. Safe cycling design requires good intervisibility between cyclists and drivers, with both parties able to see and predict the actions of the other. Hedges would remove that intervisibility, making collisions likely, especially at 'priority' junctions, where one party is required to yield to the other.
In addition, safety for people cycling at junctions will often rely on ensuring that cycleways are sited at specific distances from the main road when the cycleway crosses a side road, again to ensure intervisibility between drivers and cyclists, and to ensure that the crossing point is at a location where speeds will be low. Safety-critical design should not be adjusted or adapted, even out of a well-meaning concern to reduce the effects of pollution.
General comments
The focus on cycling in this document is largely framed around mitigating the effects of pollution on the relatively small proportion of people cycling in urban areas, and it suggests doing so in ways that, in some instances, might even reduce the amount of cycling in urban areas by making it less convenient, difficult, or even impossible.
Clearly this would be counterproductive, if it means short urban trips continue to be made by motor vehicles, instead of by non-polluting modes. A more constructive approach would be to view cycling as a solution to the problem of pollution in urban areas, and to therefore focus policy around designing roads and streets that enable cycling for everyone.