The B656 is closed after a van collided with a deer and went into a hedge on the outskirts of Hitchin.
Emergency services were called at about 5.05pm to London Road, St Ippolyts, after a man driving a van hit a deer and then went into a hedge near to the former Greyhound pub.
Paramedics were on the scene within three minutes and are currently treating the man, who is not believed to have life-threatening injuries.
As well as an ambulance, rapid response vehicle and an ambulance officer, an air ambulance was also called to the scene but it is not clear whether the crew have been required.
Firefighters were also called to reports the man was trapped, but on arrival this was not the case. Crews made the scene safe and assisted paramedics.
Police have shut London Road at the junction for Sperberry Hill.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here