Get Moving: Roading engineers use their blocks

Q: I'm enjoying watching construction of the new Esmonde Rd interchange, but there's one puzzle. What is the purpose of the large polystyrene slabs now being stacked up on the construction site? How are they going to be incorporated into the structure? Mark Fryer, Devonport.

A: One source suggests that they are leftover packaging from a very large television set. But as well as being used as packing material, polystyrene is often used to fill gaps in concrete structures, supporting the concrete as it sets and providing permanent lightweight fill. At Esmonde Rd, the poor ground between the Hillcrest Creek bridge and the busway underpass requires stabilisation, and traditional fill would be too heavy. The blocks of polystyrene you can see will be stacked together in a tray arrangement, and fixed in place with metal plates. A concrete deck will be built over the blocks, and then the road will go on top of that. Clever stuff.

Q: The road is being widened and traffic lights installed at the Sunset Rd roundabout in Glenfield ready for the joining of the two parts of Glendhu Rd. When will this join-up take place? Jo Kneller, Glenfield.

A: They like to get their preparation done early in North Shore City. All this work, to improve safety and traffic flow, is so that the linkup can take place - in four to five years. However, it will then be easier for Bayview residents to get to Glenfield Rd and the Albany Highway.

Q: Is there ever going to be a right-turn phase to the lights on the corner of Beaumont and Fanshawe Sts for traffic turning out of Beaumont St East to head north over the Harbour Bridge? This intersection is only going to get worse when the Air NZ building is occupied, and the frequent concrete trucks are already causing a problem. H. McKenna, Helensville, Bill Falconer, Mt Eden.

A: The right-turning phase will be installed as part of the Fanshawe St widening. Work on this is planned to start in October and expected to be completed in January.

Q: Are there any plans to reseal the Newmarket Viaduct? The rough surface is particularly noticeable in the outside northbound lane. Keith Hamilton, Milford.

A: Transit plans to reseal the road on the viaduct after October, when the weather should be more settled.