Stunned motorists did a double take when cyclists took to the M55 - on a tandem.
Drivers had to slam on their brakes according to witnesses when the pair were spotted happily cycling along the motorway on the way to Preston at 4.45pm on Sunday.
One witness, who took this picture, said the pair could have caused a serious accident.
Sarah Rhodes, from Kirkham, who was travelling in the passenger seat, said: “As we got on the M55 at Blackpool I immediately noticed motorists ahead slamming on their brakes.
“I presumed it was heavy traffic up ahead but as we passed Junction Four my daughter Emily pointed out the tandem weaving to the left lane in busy traffic.
“We were alarmed and called 999 immediately.
“I was horrified that someone would think travelling on the motorway on a bicycle was a sensible thing to do. They could have caused a terrible accident endangering themselves and motorists.”
It is thought the pair may have been taking part in the Manchester to Blackpool cycle ride earlier that day and were making their way home.
A Lancashire Police spokesman said: “We were called to the M55 between junctions four and three, eastbound, to reports of a tandem on the hard shoulder.
“Officers attended the scene amid concerns for the cyclists’ safety.”