Rail investment is an economical option to reduce traffic logjam in Brisbane and Perth cities compared to road, according to a new economic study.

The ‘Value of Action versus the Cost of Inaction’ study was carried out by Synergies Economic Consulting for the Australasian Railway Association (ARA).

Rail investment would save 57% and 38% of investment in Brisbane and Perth respectively, compared with road to achieve the same reduction in traffic congestion.

"Halving congestion would remove 127,000 cars from Brisbane roads."

Commuters in Brisbane are currently losing 11 million hours per year due to traffic congestion, while Perth commuters are losing 14 million hours.

ARA CEO Bryan Nye said that to halve Brisbane’s congestion levels, 2300km of road would be required, costing about $46bn, whereas rail could achieve the same reduction in congestion for 57% less or a $20bn investment.

Similarly, to reduce traffic congestion in Perth by 50%, $40bn for 2000km of road would be required, while a $25bn or 38% lower rail investment would achieve the same congestion reduction, according to Nye.

Apart from rise in vehicle running costs, congestion reduces road speed, increases travel time and pollution.

Nye further said that Brisbane and Perth will face $48bn and $33bn in economic and social costs due to congestion between 2014 and 2013, if case if no action is taken to reduce congestion.

"Halving congestion would remove 127,000 cars from Brisbane roads and 163,000 cars in Perth each peak hour, giving the average Brisbane and Perth commuter an extra 73 hours per year, the equivalent of almost two weeks annual leave."

If no action is taken to invest in public transport, the annual cost of congestion could reach $5.5bn per year in Brisbane (currently $2bn) and $3.8bn per year n Perth (currently $1.4bn) by 2013.