An overturned car on the A15 Canwick Road is blocking traffic moving out of Lincoln and causing delays in both directions.
Traffic is affected between the A57 Norman Street junction and the B1188 Canwick Road junction.
The driver was trapped for some time but once freed was taken to Lincoln County Hospital by paramedics. His injuries are not thought to be serious.
Police were on the scene, shortly after the crash at around 2pm, redirecting traffic while the incident was cleared.
The road was re-opened just before 4pm but there is still congestion in the area.