麻豆社

The introduction of 20mph limits on London's roads reduced the number of deaths and injuries, according to a report commissioned by Transport for London (TfL).

Across all 157 schemes on borough roads, there was a 34% decrease in fatal or serious casualties - although other safety features in the control group indicated it would have fallen by 15% anyway.

Walking and cycling commissioner Will Norman said the new analysis was "compelling" and "shows clearly that lowering speeds is saving lives."

But Callum McGoldrick, from the TaxPayers' Alliance, said blanket 20mph zones "risk punishing responsible drivers without delivering clear value for money."

So are they worth it? 麻豆社 Radio London's Aaron Paul has been finding out. (Image credit: Getty Images)