Upgrades
In July 2009 an upgrade of the section between the M50 junction and the Leixlip interchange was completed. On this section the road is three lanes in each direction, the median crossings have been removed and the junction with the R120 is now a fully grade-separated junction. Private accesses and some left turns remain preventing the section from being designated a motorway. The speed limit is 80 km/h. There are now no signal controlled junctions on the N/M4 between Palmerstown and the Sligo throughpass.
Read more about this topic: N4 Road (Ireland)