Last year Transport for London and 18 London boroughs implemented a new permitting scheme on roads managed by them.
The scheme requires utilities to co-ordinate work in order to reduce disruption to road users.
According to figures issued by City Hall, roadworks by utilities fell by 17% in boroughs covered by the scheme but by just 7% on roads managed by non-participating boroughs.
Mayor of London Boris Johnson, said: “Permitting is clearly having a positive effect on the roads where it is used.”
By the end of this month 27 boroughs will be full members of the scheme. The remaining six boroughs are expected to join during 2012.
