M50 N11 Merge

RoryMurphyJnr

Apologies if this has been posted before, no doubt it has but I can't find it.

Why does this stretch of road grind to a shuddering halt every single day?
The volumes can't be that much more surely than the rest of the M50

I travel from Bray to the Airport and back each day.
Half of my time spent on this trip is from made up of the journey from Cherrywood to Bray.

coylemj

Every road has a 'tipping point' when a small increase in volumes has a disproportionate effect on average speeds, the merger of the N11 traffic into the M50 is clearly having this effect.

Something similar happens on the M7 inbound on Sunday evenings where the Dublin-bound M9 merges into the M7 from a tunnel. The M7 traffic slows down to absorb the merging traffic, everything slows down but gradually speeds up again. The difference with the N11 is that in Co. Wicklow the motorway runs out and the speed limit drops so the road just cannot handle the volume and it jams up. Even though the inbound M7 also reduces to an 'N' road, it branches into three (from two) lanes at the same time so the reduction in the speed limit doesn't have a big effect on the volumes the road can handle.

Reati

I've also wondered, due to the fact it's mainly a rush hour thing and the cost of works wouldn't likely be considered worth it - what could, if anything, be done to fix this?

coylemj

Reati wrote: »

I've also wondered, due to the fact it's mainly a rush hour thing and the cost of works wouldn't likely be considered worth it - what could, if anything, be done to fix this?

Either add another lane or build a giant flyover to bypass Kilmacanogue and leave the elevated section designated as a motorway with a 120 kph speed limit.

Jamie2k9

coylemj wrote: »

Every road has a 'tipping point' when a small increase in volumes has a disproportionate effect on average speeds, the merger of the N11 traffic into the M50 is clearly having this effect.

Something similar happens on the M7 inbound on Sunday evenings where the Dublin-bound M9 merges into the M7 from a tunnel. The M7 traffic slows down to absorb the merging traffic, everything slows down but gradually speeds up again. The difference with the N11 is that in Co. Wicklow the motorway runs out and the speed limit drops so the road just cannot handle the volume and it jams up. Even though the inbound M7 also reduces to an 'N' road, it branches into three (from two) lanes at the same time so the reduction in the speed limit doesn't have a big effect on the volumes the road can handle.

That's one way of putting it, not the way I would use.

Chris_5339762

This is a big weaving section where traffic off the N11 from Donnybrook travelling south along the Bray bypass meets traffic coming from the M50 going south. Some of that is traffic trying to battle its way across lanes to go into Bray itself.

It could be solved but would involve a lot of flyovers and be very expensive.

loyatemu

4 lanes merging into 2 in the space of about 1KM, plus a lot of weaving. Congestion is inevitable.

There are plans to provide a 3rd lane as far as J7 and a parallel collector road to close some of the minor junctions/accesses between J5 and J8. No timetable for this though.

patrickbrophy18

loyatemu wrote: »

4 lanes merging into 2 in the space of about 1KM, plus a lot of weaving.

That would put a new meaning to the word Avoca Hand Weavers?;)

Anyway, to answer the question submitted by the OP. If your point of origin is Bray and your destination is the Airport, you could avail of the 702 Aircoach. Alternatively, there is Wexford Bus with a stop at Kilmacanogue.