The Police Service collect data on road traffic collisions involving injury. At the moment, the datasets for 1998 to 2014 are on the UK Data Service (https://discover.ukdataservice.ac.uk/); however, with 'standard', rather than open, licensing. This limits the accessibility of the data, and limits the use and benefits of sharing information learned from its existence.
The PSNI currently publish details of fatal road traffic casualties on a daily basis, even with that data being marked as provisional (http://www.psni.police.uk/index/updates/updates_statistics/updates_road_traffic_statistics.htm) The annual datasets themselves have been put into the public domain in response to FOI requests, e.g. http://www.thedetail.tv/articles/two-years-of-death-and-serious-injury-on-northern-ireland-s-roads
There is therefore a cause for providing this data under an open licence, as with the corresponding road safety (STATS19) data for GB https://data.gov.uk/dataset/road-accidents-safety-data