Motorists in Lochaber suffered long tailbacks due to a massive cycling event on the A82 Inverness to Glasgow road yesterday.
There were also reports of drivers attempting to overtake larger groups of the 800 cyclists taking part in the face of oncoming traffic.
And a spokesman for the A82 Partnership campaign group last night said only “good fortune” had prevented a serious accident from happening.
The cyclists were taking part in the sponsored Deloitte Ride Across Britain Land’s End to John O’Groats charity event.
They set off from Hamilton to cycle to Fort William yesterday morning and started arriving in Lochaber early afternoon.
A82 Partnership spokesman Stewart MacLean said: “There were lots of hold-ups.
“It’s only down to good fortune that there wasn’t a serious accident.
“When I drove from Fort William to Onich at around 5.30pm I met four cars in the middle of the road trying to overtake large groups of cyclists.”
He said some of the cyclists were travelling alone or in small groups of three or found, but he also passed large groups of 12-15 bikes with queues of more than 20 vehicles behind them.
“This was obviously causing frustration and some motorists were pulling out onto the wrong side of the road inappropriately in an attempt to overtake them,” said Mr MacLean.
The cyclists will be back on the A82 this morning as they head from Fort William to Fort Augustus, before taking the road to the south-east side of Loch Ness to Inverness.
Event organiser Nick Tuppen, of Threshold Sports, said: “I’m sorry to hear that some participants have not been following the rules of the highway code.
“Throughout our communications with the riders, we always stress the importance of safe riding.”
He added that any participants seen riding dangerously would be dealt with immediately, including removing them from the event if they were considered a danger to themselves or other road users.