20mph Case Study
20's Plenty for Watford's Feasibility Study - Mott Macdonal Report (2018)
In 2018, 20’s Plenty For Watford and Watford Borough Council successfully bid for a grant from the Herts Police and Crime Commissioner’s Road Safety Fund, which, enabled the commissioning of a report from Mott Macdonald (engineering, management and development consultancy) to assess different options for delivering 20mph schemes in Watford.
Mott MacDonald’s study of Watford found that Herts County Council had spent more than
£3 million to install 20mph limits covering just one third of the town. This would mean that their Speed Management Strategy (SMS) approach would cost around £10 million to cover the whole of Watford - the smallest, by area, local authority in the country. The County Council's approach relied heavily on expensive speed bumps and other engineered solutions.
If, rather than using a strategy that relies heavily on unnecessary engineered solutions, Herts County Council had used the wide-area approach adopted in places such as Portsmouth, Bristol and Bath & North-East Somerset, it would have cost less than £500,000 to make Watford a 20 mph town - a difference in cost of £2.5 million.
It is estimated that Herts County Council's approach to implementing 20mph speed limits is
10 times more expensive than necessary to satisfy Government guidelines and policy.
20's Plenty for Herts estimate that using a non-engineered, wide-area approach (with signs, speed enforcement and community engagement), 20mph speed limits could be implemented across the majority of urban and residential roads across the county for an estimated cost of £3.3 million (based on Hertfordshire population of 1.1million at a cost per head of £3 per head.)
You can read the Mott Macdonald Report summary below and the full report here.