Blanchardstown Interchange
| Blanchardstown Interchange | |||
| Location Map ( geo) | |||
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| View of the M50 from the Canal Bridge at night | |||
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| Location | |||
| Castleknock | |||
| County | |||
| Dublin | |||
| Highway Authority | |||
| Transport Infrastructure Ireland | |||
| Junction Type | |||
| Unique | |||
| Opening Date | |||
| 1990 (rebuilt 2010) | |||
| Roads Joined | |||
| M50, N3, R147, R806 | |||
| Junctions related to the R147 | |||
Blanchardstown Interchange is junction 1 of the N3 and junction 6 of the M50. It is well-known for its elaborate road layout, with several flyovers.
The modern junction actually consists of three former junctions. The main Blanchardstown Interchange was opened in 1990 to serve the West-Link Bridge. The M50 was extended north of here in December 1996. This junction was built as a standard roundabout interchange, straddling the Royal Canal and the Sligo railway.
The N3 had two much smaller roundabouts as it approached this one. Blanchardstown Roundabout to the west (widely known as 'Scott's Roundabout' at the time) was the junction between the Blanchardstown Bypass and the old Main Street through Blanchardstown Village. It later provided access to Connolly Hospital. The flyover that replaced it is officially recorded as 'Scott's Junction'.
To the east, Auburn Avenue Roundabout provided access to Auburn Avenue and Dunsink Lane, serving Castleknock.
The roundabouts became unworkable as traffic levels rose not just on the M50 and the N3, but also in the rapidly-expanding suburbs around Blanchardstown, including the large shopping centre. The redesign, completed in 2010, effectively merged these three junctions into one.
Despite the new road layout, the junction does still suffer from congestion, primarily due to the poor alignment of some of the underpasses. A mandatory 30km/h speed limit applies to some of them, including one ramp that is colloquially known as "the corkscrew", for its sharp turns.
In 2012, the N3 into Dublin was downgraded to R147. The shortened N3 now starts here.
The original plan for the M50 showed no junction here, with the Navan Road crossing the M50 without an interchange. Instead the M4 would have had an interchange with the M50 close to here, at Castleknock.
Either side of the roundabout are two bridges of the canal. Talbot Bridge to the west is now a cul-de-sac, while Ranelagh Bridge to the east now acts as a pedestrian crossing.
Fly-through
Routes
| Route | To | Notes |
| O Thuaidh/NORTHBOUND, Aerfort Átha Cliath/DUBLIN AIRPORT, Calafort Átha Cliath/DUBLIN PORT | ||
| Toll, O Dheas/SOUTHBOUND | ||
| Beal Átha Seanaidh/BALLYSHANNON, An Uaimh/NAVAN 38km, Baile Bhlainseir/BLANCHARDSTOWN 1km, An Cabhan/CAVAN, An Larionad B. Bhlainseir/THE BLANCHARDSTOWN CENTRE | ||
| An Lar/CITY CENTRE, Caislean Cnuce/CASTLEKNOCK | Former N3. | |
| Lár Baile Bhlainseir/BLANCHARDSTOWN VILLAGE, Caislean Cnuce/CASTLEKNOCK | ||
| An Lar/CITY CENTRE, Caislean Cnuce/CASTLEKNOCK |
| Blanchardstown Interchange | ||
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