control and Supervisory Control and Data Acquisition (SCADA) system. External photocells linked to the SCADA system provide a level of tunnel lighting most compatible with ambient light levels outside. To assist drivers in adjusting their eyes, lighting gradually brightens as they approach an exit. Jet fans located within niches in the roof of the immersed tube sections provide longitudinal ventilation, and the tunnel is equipped with fire and life safety equipment. Despite the cost of its construction and operation the tunnel is not tolled. The Feasibility Study for the tunnel envisaged that the crossing could have a toll of 30 pence (in 1981 IR£) (approximately €1.07 in 2020), but the concept of a toll was dropped after political opposition. It was felt that, because of the proximity of the tunnel to the city, the imposition of tolls would tend to encourage some drivers to avoid the tunnel and continue using the city centre streets thus minimising the benefits of the tunnel. An immersed tube tunnel of similar length has been constructed in Limerick, as part of Limerick's south ring road. The Limerick Tunnel was constructed under a Public-Private Partnership scheme signed with Direct Route (Limerick) Ltd. and is tolled (and has resulted in some political opposition in Limerick as the Jack Lynch Tunnel is also an inner city relief route but is not tolled). See also Roads in Ireland References External links Official website Road tunnels in the Republic of Ireland Roads in County Cork Tunnels completed in 1999 Immersed tube tunnels in Ireland 1999 establishments in Ireland