NZ roads are not coping with heavier trucks
24th June 2019.
What a joke to see the truckers in the news, upset at the state of our roads, so they are taking pictures to give to Government to fix the roads.
When they were the ones that have almost destroyed them by forcing NZTA to allow ‘bigger, longer, heavier’, trucks on our regional roads that have no ‘under base’ solid enough to carry their ‘bigger, longer, heavier’, trucks in the first place.
These truckers were warned about our roads being destroyed back when they lobbied for the HPMV 63 tonne trucks back in 2005 by Australian roading engineers who already found that placing bigger longer, heavier, trucks on their light roads would do the same there.
So truckers ‘don’t cry wolf now’ since we all know it was your trucks that have been responsible for wrecking our public roads that you as the ‘current user’ should now pay for fixing them all under “the user pays policy”.
Best you get behind using rail to move your freight as the costs to maintain our roads are now bankrupting us all, and is now calling for common sense to use rail now.
Or use this logic and follow the ‘Michigan US’ plan.
“Experts weigh in on how much Michigan’s heavy trucks damage the state’s roads.
Paul Egan, Detroit Free Press Published 6:30 a.m. ET April 19, 2019 | Updated 10:11 p.m. ET April 19, 2019
LANSING — Michigan’s highest-in-the-nation gross truck weights are responsible for significant damage to state roads and bridges, experts say, despite years of denials from the Michigan Department of Transportation.
The issue is an important one as residents consider Gov. Gretchen Whitmer’s plan to “fix the damn roads” by hiking the tax on both regular and diesel fuels by 45 cents per gallon but not changing Michigan’s truck weight laws.
The plan would raise an extra $2.5 billion a year, of which $1.9 billion would be spent on roads and bridges.
For years, MDOT has had a ready answer when motorists draw a link between roads that are ranked among the nation's worst and a truck weight limit of 164,000 pounds that is more than double the federal limit.
It's not the total weight of the truck that matters — it's the amount of weight carried by each truck axle, the department has insisted.
And a 164,000-pound truck with the 11 axles that Michigan requires actually spreads the load more than a standard five-axle truck weighing 80,000 pounds, the federal limit.
That's not true for bridges, experts say, and only true for roads with respect to certain types of damage if the pavement the truck travels on is a smooth one. Send that same heavy truck bouncing down a road that is already rough — as so many Michigan roads are — and a different set of physics applies.
In interviews with civil and mechanical engineers and a review of academic literature, the Free Press found:
• Even on a smooth road, studies show gross vehicle weight — not axle weight — is directly related to a type of damage called "rutting," which is a permanent depression in the pavement along the path the wheels follow, and which is related to road roughness. Conversely, for road fatigue and cracking, civil and mechanical engineers agree that axle weight, not the total truck weight, is the critical factor.
• Trucks that bounce on rough surfaces create a "dynamic loading" effect that is significantly higher than what results from the weight of the truck when it is standing still or moving on a smooth surface. Engineers disagree over whether gross weight or axle weights take precedence when trucks start to bounce, but they agree both are part of the calculation.
• When it comes to damage to bridges, it's all about the truck's total weight, not the axle weights, engineers agree. That's because a bridge bears the entire weight of a truck, regardless of how many axles the truck has. A 2016 U.S. Department of Transportation study estimated that raising the federal weight limit from 80,000 pounds to 97,000 pounds would necessitate $2.2 billion in bridge improvements to handle the extra loads.
Larry Galehouse, founder and past director of the National Center for Pavement Preservation at MSU and a civil engineer who worked more than 20 years at MDOT, told the Free Press that Michigan's high gross weight limits contribute significantly to road damage.
"When you get a road that's not smooth, you get dynamic loading, which is a truck bouncing up and down," Galehouse said.
Not just the axles, but the entire weight of the bouncing truck crashes onto the pavement, and "it has a tendency to really tear up the roads," Galehouse said.
Both the bouncing axles and the bouncing truck body can deliver hammer blows to a rough road, since doubling the load of an axle produces 16 times the damage, based on a rule of thumb used by civil engineers.” UN QUOTE.
• So now ‘the truth is out there’ in a 2016 U.S. Department of Transportation study that has estimated that “raising the federal weight limit from 80,000 pounds to 97,000 pounds would necessitate $2.2 billion in bridge improvements to handle the extra loads.”
So now have those ‘heavier trucks’ already everywhere on our roads; - what do we do about our roads that are falling apart in front of our eyes daily now?
Our only viable option is to use rail.