The Standard understands the collision on the A15 Sleaford bypass this afternoon is between a car and a motorbike.
The road was re-opened at 7pm, according to police.
Friday, - Emergency services are attending a road traffic collision on A15, near Sleaford this afternoon (Friday).
The force control room confirmed that it had been called at 4.52pm and that officers were just arriving on scene.
Motorists are reporting that the road has been blocked and they are being forced to turn around.
There are reports that an air ambulance is in attendance.
Sleaford police have also Tweeted: “A15 Sleaford Bypass closed due to RTC please find another route. Drive safely pls RT”
A motorist told The Standard: “I was driving from Holdingham roundabout towards Sleaford on the A15 and the traffic was going very slow.
“I didn’t get very far along the A15 when the traffic virtually came to a standstill. We turned around and all I could see were police cars and ambulance cars.
“The air ambulance was also circulating overhead and I think it must have landed.
“As I was driving back towards the Holdingham roundabout two more police cars and an ambulance car went past.
“It must be very serious.”
More details as we find out.