OBJECTIVES REDUCE THE COST OF MAINTAINING ROADS, BY PREVENTING THE - - PowerPoint PPT Presentation

OBJECTIVES

REDUCE THE COST OF MAINTAINING ROADS, BY PREVENTING THE DAMAGE CAUSED BY OVERLOADED VEHICLES.

Armidale Regional Bellingen Coffs Harbour Dungog Kempsey Port Macquarie/ Hastings Liverpool Plains MidCoast Muswellbrook Nambucca Tamworth Regional Upper Hunter Uralla Walcha

Mid North Weight of Loads – Member Councils

WHAT WE DO?

 Liaise with Operators to assist with legislative

compliance.

 Work in conjunction with the NSW Department of

Transport (previously RTA) to ensure that the following Acts (& regulations) are complied with:- Road Transport Act 2013 with associated Road Transport (General) Regulation 2013 but also Road Regulations 2008, Road Rules 2008, Road Transport (Vehicle Registration) Regulation 2007, Road Transport (Mass, Loading & Access)Regulation 2005 (only partially repealed) and also Heavy Vehicle National Law (NSW), Heavy Vehicle (Mass Dimension Loading) Regulation and of course the Local Government Act(covers officer Authorisations from each LGA).

 Patrol State, Regional and Local roads in the

participating council areas.

 Conduct random mass checks on heavy vehicles to

ensure they operate within legislated mass limits

WHY?

Because overloaded vehicles cause excessive damage to roads and bridges and the cost to the community to repair the damage is extremely high Pavement damage can be a contributing factor in vehicle accidents Local government roads are low volume roads covering vast distances; because of limited funding these roads were built with limited pavement thickness and are most vulnerable to effects of overloaded vehicles.

Belltrees Bridge, Scone Shire Council March 1921 Anticipated vehicle use !

Belltrees Bridge, Scone Shire Council October 1996

Could a bridge designer of the 1920’s have foreseen a Super-Dog combination or a B-Double ?

WHAT IS THE EFFECT OF OVERLOADING ON THE ROAD ?

ESA

• An ESA is an Equivalent Standard Axle
• A Equivalent Standard Axle is defined as a Dual Tyred

Single Axle transmitting a load of 80kN (or 8.2 tonne) to the pavement.

Standard Axle is 5.4 tonne on Single Axle Single Tyre 8.2 tonne on Single Axle Dual Tyre 13.8 tonne on Tandem Axle Dual Tyre 18.5 tonne on Triaxle Dual Tyre

The 4th Power Rule

4 No of Load on Standard = Axle Group Axle Standard Repetitions Load for Axle Group

Application of the 4th Power Rule

Effect of a 5% overload – 4th power rule increase in damage 1.05 x 1.05 x 1.05 x 1.05 = 1.22 i.e.22% Or, Reduction in pavement life 0.22/(1+0.22)=0.18 i.e. 18% The effect of 10% overload 1.10 x 1.10 x 1.10 x 1.10 = 1.46 Or 46% increase in damage and 32% Reduction in pavement life

Overloading vs Pavement Life

Note the effect of 20% overloading halves pavement life by fatigue loading Working life of % overload % increase 20 year pavement On “Standard Axle” in damage reduced to (years) 10 46 13.7 20 105 9.8 30 185 7.0 40 285 5.2

Designs are based on equivalent no. of standard axles.

kN Tonnes ESA Single Axle Single Tyre 53 5.4 1 Single Axle Dual Tyres 80 8.2 1 Dual Axle Dual Tyres 135 13.6 1 Tri Axle Dual Tyres 181 18.5 1 Equivalent No. Standard Axles = AXLE WEIGHT Exponent STANDARD Exponent: - Granular = 4 Sub Grade = 7.14 Asphalt = 5 Bound (Cement Stab)= 18 Example – Effects on Fatigue Life – Dual Axle – Dual Tyres

Load ESA Bound – (Cement Stabilised) Gravel Pavement Sub Grade Asphalt 1ESA 1.0 1.0 1.0 1.0 Current Legal Load (16.5) 2.17 3.98 2.63 32 Available Permits - up to (18.0) 3.07 7.4 4.06 155.3

Damaging Power of Overloads (Ex Wilks) Reduction in Pavement Life Due to Overloads

Car vs Truck

To help put in context

=

2 Tonne Car = 1/2250th ESA’s Ave Artic Truck = 2.65 ESA Artic Truck = 6000 Cars

 82% of traffic on National Highways

are cars

 Cars contribute 0.03% to pavement

loadings based on ESA – km travelled

Car vs Truck

“Road” Friendly Suspension ? ? ?

AIRBAGS VS STEEL SPRINGS RTA test conducted on a 4 short span reinforced concrete bridge on the Bucketts Way, in Great Lakes Council area.

Bridge 4 x 9.14m spans P/S Concrete

The GVM is the structural capacity as determined by the Manufacturer

Mass Limits Vs Gross Vehicle Mass

GVM may be found on the rego label or in the cabin And should be printed on right side of the vehicle

Mass Limits Vs Gross Combination Mass

 The manufacturers GCM is the maximum structural

capacity of Prime Mover & Trailer Combination.

Mass Limits

The legal mass limits for each axle or axle group and gross weights.

Mass Limits

The posted weight

• f a load restricted

road or bridge.

Exceed 1:1 Ratio

 The weight of trailer cannot exceed

the weight of the towing vehicle.

 Truck must be heavier than the

trailer.

B – Doubles Off Route

 B – Doubles must follow proscribed

routes.

 This information is available on the

RTA website (www.rta.nsw.gov.au)

• r RTA Motor Registries

The Process

Stopping – Drivers are required to stop when an

• fficer displays a notice (Whether illuminated or

not) bearing the words “STOP” or “RTA STOP”. A Fail to Stop breach report will be written if a driver fails to stop.

The Process

Safety – inspectors are able to direct the driver of a vehicle up to thirty kilometres away from the drivers direction of travel in order to utilise a safer, more suitable weigh site. Worksites are set out using approved Traffic Control Plans

Place Scales

Remove scales from boot of Weight of Loads Vehicle Place scales in front of all wheels

Establish the degree of the slope on the weigh site both laterally & longitudinally

Truck Drives Onto Scales

Place scales in front of all wheels

Scale Readings – Drivers are encouraged to view scale readings however due to OH&S requirements all directions relating to safety and the worksite must be strictly adhered

• to. This may include but is not limited to the wearing of

safety vests.

Check Weights

Calculate allowed weights Calculate axle weights Discuss any breaches Office will issue infringement if required

WHAT DOES THIS MEAN TO YOU ? ? ?

COST OF OVERLOADING TO GLOUCESTER SHIRE COUNCIL

ANALYSIS BASED ON WILKS

• Average overload = 10% (based on Mid North Weight of Loads Group Statistics 13/14)
• From Wilks this represents an increase in damage power of 60%
• Thus, the reduction in pavement life due to overloading would be 25% if all vehicles were
• verloaded.
• However, only 5.8% of all vehicles stopped were overloaded.
• Reduction in

= 100 x (% increase in damaging power) x % of vehicles overloaded Pavement Life (100 + % increase in damaging power) = 100 x 60) x 7.3 (100 + 60) 100 = 2.7 %

• Length of sealed road in Gloucester Shire = 315 km
• Unit cost for gravelling / stabilising and sealing $250,000/km
• Therefore replacement value of sealed Road Assets = $79m
• Distributed over a nominal 20 year life = 79 x 106 = $3.95m pa

20

• Cost of Reduction in life of roads due to overloading = $3.95m x 2.7% = $106,,650 pa

POTENTIAL SITUATION IF NO WEIGHT OF LOADS GROUP

• Estimate that average overload would increase from 10% to at least 25%
• Hence average overload would then represent an increase in damaging power of 150%

(compared with legal loads) with a corresponding reduction in pavement life of 55% if all vehicles overloaded.

• Estimate that the % of vehicles overloading would increase from 7.3% to at least 25%
• Therefore, expected reduction in pavement life =

100 x ( 150 ) x 25 = 15% 100 + 150 100

• Cost of Reduction in life of roads due to overloading

= $3.95m x 15% = $592,500 pa

Benefit of MNWOL Membership

• Annual potential savings in road life = $592,500 – $106,650 = $ 485,850
• Cost to Gloucester Shire Council to operate MNWOL (Currently pa) $13,800
• Hence, economic benefit / cost ratio = $ 485,850 = 35

$ 13,800

Watch your Weight