Officers were called to reports of a kidnapping in Gloucester only to find it was a stag do prank.
Police said a distressed woman and her daughter saw four men with tights over their faces carrying a tied-up man and bundling him into a car on Friday.
Officers were mobilised and eventually stopped two vehicles on the M5 near Bridgwater in Somerset two hours later.
There it was established that the incident had been carried out as part of a stag party.
'Words of advice'
Insp Arman Mathieson, from Gloucestershire Police, said: "We received a 999 call at 11.20am from a distressed woman who, along with her 14-year-old daughter, had seen four men with tights covering their faces carrying a tied up man and bundling him roughly into a car.
"We immediately sent officers to the scene and treated it as a genuine abduction, following up all the appropriate procedures for an incident of that sort.
"The vehicle was linked to Chippenham in Wiltshire, and was believed to be heading for the M5, so we liaised with our partner forces.
"At around 1.30pm the vehicle was stopped by Avon and Somerset police at junction 24 of the M5, when it was established it was a 'prank' as part of a stag party."
The inspector said it was a "good example of police work, in that we were able to work with two neighbouring forces to find the vehicle - for which we only had a partial index number - many miles away, stop it and establish what had happened".
He added: "While we could arrest the people involved in the stag party for various offences, we feel the best course of action might be for them to apologise to the mother and daughter who witnessed this and who were very shaken up by what happened."
An Avon and Somerset Police spokeswoman said the occupants of the vehicles had been given "words of advice".
"While this may have been considered a harmless prank a significant police response was unnecessarily diverted through heavy traffic and adverse weather to attend this incident," she said.
"This could have jeopardised the safety of members of the public, the officers involved or our response to a genuine emergency."