The number of people arrested over climate change protests that blocked five M25 junctions has reached 77.
Activists from a group called Insulate Britain caused long tailbacks and disruption with the action on Monday.
Fiona Atkinson from the group said it was "fed up with the lack of action" on the issue, but the government said it was supporting people to install energy efficiency measures in their homes.
Police thanked drivers for their "patience and understanding".
There were protests at junctions 20 for Kings Langley, Herts, 14 for Heathrow terminal four, three for Swanley in Kent, six for Godstone, Surrey and 31 for Lakeside, Essex, on Monday.
Police were first called at about 08:00 BST and junctions were fully reopened by lunchtime.
Hertfordshire Police said it arrested 18 people, while Kent Police and Essex Police arrested 12 each.
The Essex force said nine had been released under investigation, while three were released on conditional bail.
Surrey Police said it arrested 35 people with 15 released on conditional bail and the rest released under investigation pending further inquiries.
Arrests were made for various offences, including public nuisance, obstructing the highway and conspiracy to cause danger to road users.
Det Insp Chris Friday from the Surrey force said: "Protesters ignored police requests to move on, so we took robust action to enable the motorway to be reopened.
"A number of people were taken into custody and enquiries are progressing."
He also thanked "all those motorists who got caught up in the delays".
Ms Atkinson from Insulate Britain said there was "not enough progress" on insulating homes.
She told BBC Three Counties Radio the protesters had acted to generate discussion and media coverage of the issue.
"What we haven't been able to do, pressure groups, is get the government to act," she said.
"As soon as the government say they are going act we'll get off the road."
A government spokeswoman said: "People's day-to-day lives should not be disrupted, especially on busy motorways where lives are put at risk and resulting traffic delays will only add to vehicle emissions.
"We are investing £1.3bn this year alone to support people to install energy efficiency measures, and our upcoming Heat and Buildings Strategy will set out how we decarbonise the nation's homes in a way that is fair, practical and affordable."