M8 motorway (general thread)

I don't think so - it would be a lot of money to save a small amount of drivers a small amount of time.

A direct interchange would be stupid, conisdering how the two roads meet: you’d be making a long hairpin.

M8 is missing a J2 south of the split, and N7 is missing a J20 west of the split. That’s how the movement would be handled, but there’s really not much in the way of a traffic source or destination that needs to be accommodated here. Most motorists will have turned off M8 further south, or will leave N7 further West.

That DC is the M8. N8 was dualled in stages from the 1990s to the end of the 2000s. In 2008, all of those "High Quality Dual Carriageway" primary roads were redesignated as motorways:

 https://www.irishtimes.com/news/just-under-300km-of-roads-upgraded-to-motorway-1.945503

The original junction between N8 and M7 was to be at M7 J17 Portlaoise, here (choose “more dates, 2009” if it doesn’t show the old image: County Laois - Google Maps

Note the extra left lane behind the barricade blocks. This was to provide a “free flow” join from M7 to N8, but to my knowledge it was never opened to traffic. It was removed sometime in the early 2010s.

Sometime in the early 2000s, the junction was moved west of Portlaoise, most likely to allow a bigger interchange, but also to shorten the total amount of motorway needed: the old N8 (now N77) is 28 km from M7 J7 to the northern end of the N8 Urlingford bypass, with the current layout it is just 13 km.

There would have been no toll back in the days when N8 was not planned as a motorway - in those days (pre-2000), tolling was only applied to bridges and tunnels, although lobbying from Cork TDs prevented the Lack Lynch Tunnel from being tolled. I believe the new M7/M8 interchange was planned without a toll, but by the time it came to design, it had been decided to build this as a PPP, with the toll revenue going to the private funder of the build (Celtic Roads Group).