Christchurch drivers see red at right turns
Christchurch motorists say they are fed up with post-quake road chaos that is aggravated by a lack of right-turning arrows at problem intersections.
Hundreds of Press readers went online to identify city intersections where turning right across oncoming traffic is a challenge made worse by congestion and road works.
Traffic officials have called on motorists to be patient as thousands of adjustments are made to the system each month to help it cope with "abnormal" post-quake traffic patterns.
"Nightmarish" intersections identified by motorists included Innes Rd and Cranford St; Brougham and Montreal streets; and Matipo St and Blenheim Rd.
Christchurch resident Keith Paterson said the intersection of Glandovey and Strowan roads and Rossall and Heaton streets was particularly bad with drivers frequently running red lights.
Other readers admitted to risking a crash and turning on a red light in frustration or taking unusual shortcuts through petrol station forecourts near intersections.
The Christchurch Transport Operations Centre (CTOC) manages the city's roads post-quake and recommends changes to the city council and NZ Transport Agency.
CTOC manager Ryan Cooney said the transport challenges were huge and adjustments made to maximise the current system had skyrocketed from 700 a month pre-quake to more than 2100.
A major factor was population shift.
The transport system was built around a vibrant central city, which would eventually return. Making permanent changes now could mean costly reversals later down the track.
Unfortunately for vexed right-turning drivers, any delay to right-turning vehicles would have to be large to warrant delaying the majority travelling straight through.
One arrow installation cost $5000 to $30,000 and decisions were complicated.
CTOC could not create time, it could only reallocate it. To install a right-turning arrow for one route, green-light time was taken from another, or reduced over the hour. Green lights would then be shorter or less frequent, delaying another route.
A right-turning arrow required a minimum of 15 seconds green-time.
If the route was an arterial or freight route like Blenheim Rd, it was unlikely a right-turning arrow would be approved.
At the Matipo St and Blenheim Rd intersection, an arrow would delay 650 Blenheim Rd drivers every hour for 150 drivers turning right out of Matipo.
Cooney said right-turning arrows were not the only option.
By making an intersection's green lights shorter, more could be squeezed into an hour, which meant more yellow lights, allowing cars to turn without an arrow.
Drivers needed to turn correctly into two-laned roads and merge effectively to keep traffic moving.
Police said the number of red-light tickets issued in the city was down almost 30 per cent since 2009.
Canterbury road policing manager Al Stewart said congestion prevented cars from speeding through intersections and drivers might be using more rural roads.
Some countries with similar road rules allow free left turns on red lights when safe.
A Ministry of Transport spokesman said such a rule was not supported by the New Zealand public in 2004 and was not considered safe for pedestrians.