Traffic signal improvements in Auckland are offering drivers valuable time and fuel savings.
Auckland Transport says $109,000 invested on the first three arterial roads to be treated in a four-year "route optimisation" programme has yielded an annual benefit of $7.59 million.
The most impressive result from better coordination of traffic signals has been in Symonds St, along which the council transport organisation says about 20,000 vehicles a day are having an average of two minutes each shaved off trip times.
That amounts to about 667 hours of savings and 1150 litres less fuel burned each day between Anzac Ave and Grafton Bridge - despite complaints from some drivers about the loss of road space to bus lanes.
Commuters heading north to work along Symonds St save a modest average of one minute and 12 seconds each morning, but when driving home in the opposite direction they are cutting seven minutes and 42 seconds off their trips.
Engineers attribute the far greater evening savings to the fourth southbound lane added to the motorway from the Symonds St on-ramp to Greenlane, maximising gains from better-coordinated traffic lights on the approach route.
Lesser savings have also been reported from sections of Dominion Rd and St Lukes Rd. As well as annual time savings along the first three routes in the programme of 420,086 hours a year, Auckland Transport estimates a reduction of 1388 tonnes of carbon dioxide emissions from 559,527 fewer litres of fuel burned.
More savings are expected as the $10 million programme rolls out along at least 24 other roads, although returns are likely to diminish as it progresses, given a strategy of hitting the most inefficient parts of the network first.
Auckland Transport is hailing the gains made so far as consistent with its goal of making efficient and effective use of the region's existing transport assets, amid limited resources for new infrastructure.
The initial results had chairman Mark Ford asking staff at his monthly board meeting whether the programme could be escalated.
But chief operations officer Greg Edmonds said as many traffic engineers as possible had already been allocated to the project, against a national shortage of qualified experts.
Mr Ford said yesterday that the programme was delivering very real results for the public, and showed the benefits of a region-wide approach to managing the roading network. "It augurs well for the rest of the programme roll-out," he said.
Auckland Transport's engineers are working with the Transport Agency at a new joint traffic operations centre at Smales Farm in Takapuna to review batches of signals to ensure better coordination along the target routes.