Ask Phoebe: Quieter times predicted for key corridor

Auckland City from the southwest.

I have been watching with interest as the intersection and overbridge of the Northwestern Motorway and St Luke's Rd is widened to make room for more lanes on the overbridge, and allow more lanes on the motorway beneath it.

With the overbridge getting larger, I was wondering if you knew of plans to widen the last remaining stretch of St Luke's Rd from the intersection with New North Rd?

This last short stretch is the only portion of the ring road, Green Lane West - Balmoral Rd - St Luke's Rd that stretches from the Southern Motorway to the Northwestern Motorway.

With the large green central divide, it seems that the rail bridge is the only real obstacle. Jeremy Ritson, Auckland.

The St Lukes/ Balmoral Rd Corridor Management Plan (completed in 2013) does not recommend significant changes to the section of St Lukes Rd between Great North Rd and New North Rd.

As part of the Western Ring Route improvements, the intersection of Great North Rd/St Lukes Rd and the St Lukes Interchange is being upgraded.

This is likely to reduce existing congestion and queuing issues at the northern end of the St Lukes Rd corridor. It is anticipated that the completion of the Waterview Connection will significantly reduce traffic volumes along the St Lukes/ Balmoral Rd corridor. Traffic survey data indicate that peak traffic volumes have remained stable or declined since 2003.

The predicted decline in traffic volumes along the corridor and the intersection improvements at the northern end, reduce the need for widening or providing additional traffic lanes on the section of St Lukes Rd between New North Rd and the St Lukes Interchange.

The upgrade of the Great North Rd/ St Lukes Rd intersection and the St Lukes Interchange will also provide improved facilities for walking and cycling at the northern end of St Lukes Rd.

The St Lukes/ Balmoral Rd Corridor Management Plan (CMP) recommends improving the existing cycling and walking facilities along the remaining section of St Lukes Rd to New North Rd, but retaining the existing planted median.

Can you tell me what the blank red shield road signs are supposed to tell us?

They are everywhere but seem to have no purpose or logic. Peter Miller, Auckland.

They are emergency state highway detour signs. If a major incident closes a main highway, these signs will point to a recommended detour. When in operation, a fold-down sign, at the start of the detour several hundred metres in from the state highway, will advise motorists.

• I am ashamed to admit that I was wrong about the 'carriage lamps' on the Northwestern Motorway.

They are not, as I asserted, traffic management cameras, but survey prisms used for set-out and level control of the new construction works on the causeway.

Thus it is not your sanity in question, Mr Greenbrook, but mine.