Gardaí are appealing to motorists on the N4 inbound lane to Sligo not to slow down or stop to observe a serious road traffic collision on the outbound lane.
The sudden reduction in speed is causing traffic to build up and Gardaí are concerned another collision could occur as drivers are not focused on the road.
Diversions are currently bringing traffic through Ballisodare, however, Sligo County Council are advising that there is a height restriction of 4.49m at the Carrignagat bridge on the R290.
The road is expected to be closed for a number of hours today with Gardaí continuing their investigations.
Anyone that may have witnessed the incident or who may have dashcam footage, is asked to contact Sligo Garda Station on 071 915 7000.