An idea to fix one of Tauranga's worst morning rush hour pinch-points has been ruled out by the council's transportation manager, Martin Parkes.
He has poured cold water on a collaboration between Tauranga architect Mark Wassung and the council's transport committee chairman, Rick Curach.
They proposed introducing a tidal flow system across the two-lane Turret Rd bridge. It would have meant holding cars behind traffic lights on the quiet direction of rush hour peaks while both bridge lanes absorbed the main force of traffic.
The median that separates traffic along the middle of Turret Rd would become a temporary third lane in rush hours, with Turret Rd reverting to a two-lane road outside of peak times. There was also room for a third lane on 15th Ave.
Curach said council staff told him that stopping one of the tidal flow lanes every now and then to allow traffic to cross the bridge from the quiet direction would not work.
Council transportation manager Martin Parkes told the Bay of Plenty Times that traffic modelling had shown that the tidal flow system would make congestion worse, not better.
"It would only work if there were three lanes along Turret Rd. We're doing a feasibility study to assess whether a third lane could be added to the existing Turret Rd bridge."
Parkes said if that was shown to be feasible, the council would then assess whether a tidal flow system would be worthwhile.
He said widening Turret Rd to four lanes did not have a firm date or budget, but it would not start until after widening and other improvements to 15th Ave had finished. And work on 15th Ave would not start until after the Bayfair to Baypark (Bay Link) project had finished because two main roads could not have major construction taking place at the same time.
A council report last year stated that the Hairini Link underpass, due to open later this year, would not resolve congestion issues on Welcome Bay Rd, or downstream on Turret Rd and 15th Ave.
Curach said three-laning Turret Rd bridge had earlier been ruled out was because it could not sustain the extra loading. "If they come back and say 'Yes you can put three lanes across the bridge', that would be a brilliant interim solution."
However, if the answer was no, then he believed further traffic studies should be carried out on his and Mr Wassung's collaboration. It would mean holding back cars on the quiet peak-time direction until the queue had reached 20 or 30 cars and then allowing them to cross the bridge.
Traffic coming from the busy direction would temporarily be narrowed to one lane.
A report last week to councillors from council chief executive Garry Poole said the unprecedented increase in cars queuing along Welcome Bay Rd on weekday mornings was a pressing issue.
"The extent of the traffic build-up is a surprise. We have been trying to understand exactly what's going on so that we can hopefully implement some practical solutions."
Poole said the Bay Link project may be the reason why many people who previously used Hewletts Rd now appeared to be using Maungatapu and 15th Ave to reach the city.
The underpass construction was also compounding problems for Welcome Bay residents.
He said traffic data censors were being installed on Welcome Bay Rd and Ohauiti Rd to help understand the change in traffic numbers.
"We will also be undertaking queue monitoring on Welcome Bay Rd."
A technical working group was meeting this week to see if anything could be done immediately to alleviate traffic pressure. It would also consider measures within the next weeks or months, Poole said.