It is estimated that there are 300 major and minor crossings along the border. The border is marked only by a small number of "Welcome To Northern Ireland" road signs on the UK side, placed there by the Northern Ireland Roads Service. This can make identifying the border difficult for those unfamiliar with landmarks known to locals as the crossing point. At some crossings, there are signs welcoming visitors to the relevant local government authority district or, occasionally, reminding motorists of the need to ensure that their insurance is valid in the relevant jurisdiction.