Get moving: Lane markings disappear before bridge

Q: On the northern side of the Harbour Bridge, the southbound lanes are configured for five lanes. But the markings between lanes four and five disappear quite some way before the bridge proper, which becomes a problem at night, especially if it is wet. Why does the lane marking stop? Ian Mason, Forrest Hill.

A: Transit says the gap in the marking is deliberate because it is affected by the moveable lane barrier (MLB). If the lanes were marked all the way, part of the marking would disappear under the MLB at certain times of the day, which might lead law-abiding, lane-literate motorists to drive straight into the barrier itself. The lane markings stop so that motorists can realign themselves safely. This would suggest that it's a good idea to stay out of the lanes affected by the barrier if visibility is reduced.

Q: Omahu Rd is a very busy through-road between Remuera and Great South Rds. Traffic has difficulty most of the day getting to Great South from Omahu and also from Karetu Rd across the way, and can bank up quite badly. Are there any plans to put traffic lights here? Ken Graham, Greenlane.

A: No. Council engineers have analysed crash statistics and traffic volumes at this intersection and have decided that lights are not warranted. They do appreciate that there can be hold-ups here, but rely on the inherent courtesy of motorists to allow access from side streets such as Omahu and Karetu.

Q: What plans are afoot (no pun intended) to put cycle lanes along Ponsonby and Jervois Rds? Both roads are used frequently by cyclists, with no protection at all. In Jervois Rd at least, the pavement is about 3m wide. Michael Hutching, Auckland.

A: The good news is that these are future "strategic routes" for cyclists, says the council. The bad news is that improvements are some way off, and won't be implemented until roading upgrades happen, whenever that might be. However, when they do, there will be kerbside lanes and, at intersections, those cute little green patches like there are now in Symonds St. They have the catchy title of "cycle advance stop boxes", and make life safer at the end of traffic lanes for the put-upon peddlers.

Q: How do the flashing lights on overhead bridges on motorways work? Sometimes you see them flashing and there isn't a truck in sight. How does a particular truck know it's for them? Anna Lee, Onehunga.

A: Approaching, for example, the Penrose overbridge, there are at least four places where height indicators set off an alarm, which activates the first warning sign. As the truck gets closer to the overbridge, it is measured again and a second flashing light is triggered at the overbridge itself. Terry Brown, of Transit, says it's a case of driver awareness and, if drivers are uncertain, pull over.