Feasibility Study for a 2+1 Design Solution:

Feasibility Study for a 2+1 Design Solution for the Bruce Highway:Curra to the Tinana InterchangeBEB801 Project 1103/06/2016BEB801 Project 1

Source: Wikipedia, (2015)James Wilkinson

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Out of CrisisThe Bruce Highway is the most dangerous road in Australia

Bruce Highway Action Plan: Out of Crisis$8.5 billion for upgrades to the 1700km highway

Fatal crash rate of 0.2853 per km of road per year (17 fatalities per year on average)

03/06/2016BEB801 Project 12

Source: Metcalfe et al, (2005)

Curra to the Tinana Interchange62.4km length and 8m wide pavements

Generally undulating terrain with two mountainous sections

10,000 AADT

No major upgrade planned in the next 20 years only a 12.5m pavement widening

03/06/2016BEB801 Project 13

Features of the 2+1 Design03/06/2016BEB801 Project 14

Source: National Road Authority, (2004)Third continuous overtaking lane

Widened central median generally with a cable barrier

Critical / Non-Critical Lane changeovers for equal overtaking opportunities

Left in / left out manoeuvres only

2+1 Road Cross Section Designs03/06/2016BEB801 Project 15

Source: Gazzini, (2008)

Intersection FeaturesGenerally will occur at lane changeovers

Directional traffic will drop to one lane each way

Due to left in / left out operations between intersections U turn facilities are required

03/06/2016BEB801 Project 16

Source: National Roads Authority, (2004)

Source: Gazzini, (2008)

Outcomes of 2+1 Highway DesignSignificant reductions in fatal crashes (>50%)

Elimination of head on crashes

Reductions in overtaking and run-off accidents

Bottlenecks at lane changeover point area concern03/06/2016BEB801 Project 17

Roadway TypeFatality Rate2 lane Rural Highway0.282+1 Roadway0.164 Lane Divided Highway0.19

Source: Potts et al, (2003)

2+1 Road Design SuitabilityGenerally flat / rolling terrain

AADT within 5,000 to 15,000 optimal range

Significant reduction in fatal and severe accidents03/06/2016BEB801 Project 18

Source: Google Maps, (2016)

Road Design and Planning Manual ComplianceDesign life of 40 years

Very limited applicable content

Starting and termination points for overtaking lanes on high grades

Sight Distance requirements

Flood immunity for a Q100 flood event03/06/2016BEB801 Project 19

Source: Department of Transport and Main Roads, (2013)

2+1 Design ConcernsA missing link on the Bruce Highway

Minimum requirement for 13m wide pavements

Congestion at lane changeovers

Potential for undesirable carriageway operation and sight distance in mountainous terrain

Limited flood immunity03/06/2016BEB801 Project 110

Source: Google Maps, (2016)

Curra to Tinana Interchange 2+1 Cost EffectivenessA Benefit Cost Ratio of 3.32 for a 2+1 design can be calculated

This is based on the implementation of a 2+1 road reducing the fatality rate by 50%

03/06/2016BEB801 Project 111

FactorValueDesign Life40 yearsAnnual Average Daily Traffic (AADT)10,000Cost of Human Life$2,500,000Road Length62.4kmConstruction Cost$4.3 million/kmOriginal Fatalities0.2853/kmPredicted0.1426/km

Conclusion and RecommendationsImplement 2+1 Road from Curra to the Tinana Interchange

Widen the pavement to 13m minimum to facilitate the 2+1 configuration

Implement lane changeovers to meet RPDM specifications and sight distance requirements

Provision of cable barrier

The option for duplication in the future is not impacted 03/06/2016BEB801 Project 112

Source: National Roads Authority, (2004)