Predicted bank holiday traffic chaos has failed to materialise because of a lack of sunshine, AA Roadwatch says.
Eurostar insists the RMT strike has had no impact
Rail travellers have fared less well with much of the West Coast mainline shut for major engineering works.
BA said the worst was over on Saturday after more than 100 Heathrow flights were cancelled in six days of disruption due to staff shortages.
Meanwhile, Eurostar claims a 24-hour strike by RMT members is having no effect on services.
Engineering works had been expected to cause disruption on two motorways, the M25 and M6, throughout the bank holiday weekend.
The Essex stretch of the M25, between junctions 27 and 28 clockwise, was closed from 0630 BST and 1400 BST on Saturday after a lorry carrying batteries was involved in a collision, spilling its cargo onto the motorway.
But other major problems had failed to materialise, the AA Roadwatch spokesman told BBC News Online.
While the roads and motorways were "busy" on Saturday morning and lunchtime, traffic was generally "moving relatively well" by the afternoon.
"These things are weather-dependent and, because we haven't had blazing sunshine, then people haven't been flocking to the roads", he said.
He said traffic on Sunday would again depend on the weather but he predicted the roads would be busier on Monday afternoon with people returning from weekends away.
Although some roadworks have been lifted for the weekend, motorists have been facing 40mph speed restrictions on the M25 near Heathrow airport, while a number of link roads to the Spaghetti Junction on the M6, leading to Birmingham, will stay closed all weekend.
On the railways, much of the West Coast main line - Hemel Hempstead to Lichfield and Manchester to Stockport - has been shut for major engineering works and will remain closed all weekend.
The Great Western Mainline will remain closed between London Paddington and Reading, Berkshire.
1 Great Western Mainline closed Paddington - Reading
M25 has 40mph limit junctions 12-15 near Heathrow
2 & 3 West Coast Mainline closed Hemel Hempstead - Lichfield and Stockport - Manchester
4 Link roads to M6 spaghetti junction closed
Eurostar - strike but no delays, company says
Airports - busy but no specific delays expected
Meanwhile, Eurostar communications director Paul Charles told BBC News Online on Saturday evening there had been "100% punctuality" on trains leaving London Waterloo during the day despite RMT members staging a 24-hour strike.
Customer service staff are staging the strike over pay and grades at London Waterloo and Ashford, in Kent.
"Only seven check-in related staff didn't turn up for work out of 1,300 and that has had no impact at all," Mr Charles said earlier.
But an RMT spokesman accused Eurostar of "stretching things a bit" and said all 160 of its staff were on strike.
At Heathrow, where staff shortages and technical problems were blamed for six days of disruption, things were now running "pretty normally".
A spokesman told News Online that six flights out of a total of 540 had been cancelled on Saturday but that things were generally "running smoothly".
BA chief executive Rod Eddington and 11 other directors were expected to visit Heathrow over the bank holiday weekend to boost morale.