Substandard bridges were identified at Brent and Barnet, according to the RAC Foundation.
Barnet Council was just one of ten local authorities to report a partial bridge collapse in the 2021-22 financial year.
Brent was also among the top ten local authorities with the highest proportion of its bridge stock deemed substandard.
The municipality ranked sixth, with nine of its 40 bridges classified as too weak to be used by 44-tonne trucks.
Although no substandard bridges were found in any of the other North London boroughs, in total Camden, Hackney and Enfield reported that more than £7m would be needed to bring the bridge and roadway stock to a good level, but not necessarily. Perfect condition.
This work is worth £432,000 in Camden, £1 million in Hackney and £6 million in Enfield.
The analysis was based on data provided by 196 councils in response to freedom of information requests and was carried out in partnership with Adept, a group representing heads of local authorities responsible for transport and other sectors.
Islington Council did not provide adequate data for inclusion in the study.
RAC Foundation Director Steve Gooding said: “This latest study shows the scale of the challenge local authorities are bravely facing to protect the critical road infrastructure we all depend on against the backdrop of enormous funding and resource pressures. .
“The numbers illustrate how important it is that significant sums of money are spent to address at least the highest priority work.
“Whether it’s potholes or bridges, councils can continue to fix things for a limited time before bigger cracks literally start to appear in the road network.”
Cllr David Renard, Transport spokesman for the Local Government Association, said: “Not all bridges are the responsibility of local councils, but for those that are, they are doing everything they can to ensure they are well maintained and withstand extreme weather conditions. .
“However, this is becoming increasingly challenging in the face of a backlog of nearly £12bn for our local roads to measure up to.”
A spokesperson for the Department for Transport said: “The Government is providing more than £5 billion of investment in this Parliament to local authorities across England to support the maintenance of their local road infrastructure, including bridge repairs and the resurfacing of highways to and through the country.”
List of North London boroughs showing the number of bridges in each, with the number of poor bridges in brackets.
- Barnett 72 (5)
- Brent 40 (9)
- Camden 8 (0)
- Enfield 192 (0)
- Hackley 14 (0)
- 42 (0)
- Tier 14 (0)