THE proposed construction of a River Shannon Crossing, Killaloe Bypass and other road improvements costing an estimated €40 million could remove 40% of the current traffic from the existing bridge in Killaloe.
That’s just one of the conclusions of a future traffic forecast included in a Natura Impact Statement completed by Roughan and O’Donovan Consulting Engineers on behalf of Clare and North Tipperary County Councils.
A traffic survey revealed approximately 550 vehicles cross Killaloe Bridge during the peak hour last year.
Having spent over a year in limbo, Environment Minister Leo Varadkar approved the publication of the Statutory Orders by Clare County Council for the construction of the Killaloe Bypass (€11.93m), the Shannon Bridge Crossing (€12m), Killaloe bypass (€11.93m) and upgrading works costing (€16.6m) on the existing regional road linking Ballina and Birdhill in July 2011.
In terms of assessing the proposed Shannon Bridge Crossing, Killaloe Bypass, upgrading of the regional road linking Ballina and Birdhill, the consulting engineers assumed an opening year of 2017 and a 2032 design year model.
Traffic growth factors were applied to convert the established 2011 “base” network flows to corresponding future year “base” flows. For the opening-year traffic flows, the traffic volumes from the 2011 traffic survey were projected to 2017 using NRA traffic medium growth factors from the NRA project appraisal guidelines.
The Clare and North Tipperary County Development Plans for zonings for Killaloe and Ballina were assessed and the TRICS database of traffic surveys was used to create a projection of the traffic generated by the full development of the zoned lands.
Additional traffic generated by the development of half of these lands was incorporated into the 2032 design year model.
The 2017 Forecast Traffic Flow projects 516 two-way vehicles per hour will cross Killaloe Bridge from midnight to midday if the new crossing isn’t provided and this drops to 295 if the new infrastructure is constructed.
It predicts 585 two-way vehicles will travel on the old crossing from midday to midnight if the new one isn’t built compared to 353 if the new one is provided.
The average annual daily traffic drops from 6,737 to 3,959 if the new Shannon Crossing and associated roads are provided.
According to the engineers, these results indicate the proposed Killaloe bypass and Shannon Bridge Crossing will remove 40% of the traffic from Killaloe Bridge. “The traffic that continues to use Killaloe Bridge is local traffic.
“This significant reduction in traffic across and in the vicinity of the existing bridge will free up capacity for town centre activities including future development and will provide a much improved environment for pedestrians and cyclists in Killaloe and Ballina.
“Traffic simulations show significantly reduced queuing an delays at Killaloe Bridge compared to the 2011 conditions, even after taking into account future traffic growth over this 20-year period.
“Traffic model data also indicates that the proportion of heavy goods vehicles on the proposed Killaloe Bypass, Shannon Bridge Crossing and Ballina to Birdhill improvement is 7.2%, which equates to diverting about 500 heavy goods vehicles per day from Killaloe Bridge,” the engineers stated.
The engineers predicted someone travelling from Birdhill to Ballina and on to the Killaloe to Scariff Road would save on average seven minutes during peak periods.
Accident information from previous studies shows a “significant portion” of accidents in the vicinity of Ballina and Killaloe occurred on the main approaches to the towns along the regional roads connecting Ballina to Birdhill and Nenagh as well as the Killaloe to Scariff Road between 1996 and 2002.
“Most of these accidents occurred along tight bends and blind corners where there was evidence that speeding was a main factor.
“The proposed road scheme includes the provision of roundabouts at the intersections with the existing regional roads at the R463 on the north and south side of Killaloe and at the intersection of the R494 and R496 on the south side of Ballina.
“These roundabouts will provide a traffic-calming effect on the approaches to the towns. The reduction in through traffic at Killaloe and Ballina may result in a decrease in accidents in these urban areas,” the engineers added.