I wrote a short time ago on why the York Street Interchange and the Sydenham Bypass upgrade should be carried out jointly.
In practice, it is clear that this means the money would not be in the budget to complete the project this decade. This is no bad thing, for two main reasons.
Firstly, it is already risky to be carrying out the (already flawed) A6 Randalstown-Castledawson upgrade (given it is on the same broad northwestern corridor that ends at York Street) at the same time, as is currently proposed. Indeed, adding in the A5 Derry-Strabane project leads some to doubt the construction capacity exists to do all of these at once (I am instinctively not so pessimistic, but also no expert – so I have to consider this problem as at least possible).
Secondly, we have to consider the congestion which will be caused by the roadworks, not just at the Interchange itself but across the whole of Greater Belfast (anyone caught in last month’s two-hour jam will attest to the fact the Interchange is a pinch point affecting the whole city and its environs).
Specifically, it strikes me that construction should be postponed from its currently proposed September 2017 start date until at least until the A6 upgrade is complete and the Belfast Rapid Transit system is in operation. This latter is a guided bus system (the one for which the notorious “bus lanes” have been put in place) which will offer a more reliable public transport service along corridors not served by trains, and which will serve to relieve congestion. Having been delayed, it is now due for commencement in September 2018, but it will take some further time for gremlins to be nudged out of the system so that it has the full desired effect.
Another consideration is that, although York Street is a congestion pinch point, it is not fundamentally unsafe. Only this month we saw another tragic fatality at a gap junction on a major interurban dual carriageway (the two main examples of this are the A1 Hillsborough-Newry and A26 Antrim-Ballymena). If the money currently allocated to major road projects were allocated to the A5 and A6 as proposed but not yet to the York Street project, money would be available instantly to construct the five safer grade-separated junctions on the A1 planned as far south as Banbridge, and to plan those necessary on the A26 and A1 between Loughbrickland and Newry. The focus in the early ’20s would then become closure of all gaps, and then construction of the York Street Interchange alongside the Sydenham Bypass upgrade at a time when Greater Belfast and its motorway and mass transit corridors are better prepared for the traffic disturbance caused.
This would, of course, require strategic thinking. Whatever next?!