Zero Carbon Streets: 20’s Plenty for Cambridgeshire

This article was published in 2021, in Magazine 152.

The 20’s Plenty for Cambridgeshire campaign, which began in spring 2021, is calling for wide-area, default-signed 20mph limits with public engagement for the whole county. The campaign is part of the national 20’s Plenty for Us movement, which includes over 400 local branches, all of which are campaigning for a default speed limit of 20mph to replace 30mph.

Newspaper clipping about 20's Plenty for Cambridgeshire
20s Plenty Cambridgeshire co-ordinator Diane Fitzmaurice has worked hard this year gaining great media coverage for the campaign, but is now looking to hand over the role.

It was my experiences of feeling unsafe while cycling on, walking beside, and crossing the 30mph roads of Cambridge city that prompted me to become a campaigner for lower speed limits. The unsafe feeling I have when using these roads is not unfounded or irrational: the link between vehicle speed and risk of injury or death is well established.1 Additionally, as a Cambridge resident, I am never very far from the noise of traffic. The overall damage to public health caused by passive exposure to traffic noise is likely to be far greater than the damage caused as a result of collisions.2 Slower is quieter; reducing vehicle speeds would cut the noise3 and its damaging effects. Another unpleasant aspect of Cambridge’s roads is the smell of noxious fumes hanging in the air. Cambridge is blighted by air pollution, which is caused by emissions from traffic. Following the 2020 ruling by the Coroner, Philip Barlow, in the case of the untimely and tragic death of Ella Adoo-Kissi-Debrah, we know, unequivocally, that air pollution is a killer.

As well as being unhealthy for people, motorised traffic is also bad for the environment. In the UK, transport is the largest source of emissions of the greenhouse gas CO₂ with the majority of emissions from transport being from road transport.4 Can 20mph speed limits play a part in the battle to cut carbon emissions? The answer is a resounding ‘yes’. There is a growing body of evidence from around the world that the introduction of 20mph speed limits has a positive impact on levels of active travel. Lower-speed roads help to create places where human activities, such as walking, cycling and talking, take precedence over the movement of traffic. Each and every journey taken on foot or bicycle instead of by car is one that results in fewer carbon emissions. The introduction of low-speed roads – in tandem with public education, enforcement and cycle infrastructure – has a crucial role to play in the move towards zero-carbon mobility.5

Levels of public support for 20mph limits in Britain are consistently high6 and Cambridgeshire is no exception. The parish/town councils of Burwell, Duxford, Harston, Hilton, Ickleton, Milton, Soham, Toft, Waterbeach and Willingham have, this year, passed motions to support the aims of 20’s Plenty for Cambridgeshire. Residents of Cambourne have also voted for 20mph limits in their town.

There is no downside to 20mph speed limits. The evidence that they are beneficial to public health, as well as combating the climate crisis through promoting active travel, is too compelling to ignore. Cambridgeshire County Council sets the county’s speed limits as Highways Authority, so 20’s Plenty for Cambridgeshire encourages people to write to their county councillors to ask them to support a change in the county’s default speed limit from 30mph to 20mph.

20’s Plenty for Cambridgeshire meets online and all are welcome to join us. Our meetings provide an opportunity for Cambridgeshire’s local groups (of which there are ten) to come together. I need to step back from the role of county lead this year, but would welcome someone to continue this important work. Please email if you can help.

Diane Fitzmaurice


  1. World Health Organization. (2021). Road Traffic Injuries.
  2. Rossi, I.A., Vienneau, D., Ragettli, M.S., Flückiger, B., and Röösli, M. (2020). Estimating the health benefits associated with a speed limit reduction to thirty kilometres per hour.
  3. Mitchell, P. (2009). Speed and road traffic noise.
  4. Office for National Statistics. (2020). 2019 UK greenhouse gas emissions, provisional figures.
  5. McDonald, Z., Fulton, L., and Mason, J. (2015). A global high shift cycling scenario.
  6. Department for Transport. (2019). National Travel Attitudes Study.