Wednesday, November 18, 2009

Wheels Magazine: Winter tire recommendation means four, not two
Mothers of New Brunswick teens killed in school van crash shocked to find inquest directives not followed

Click here to read full article in Wheels Magazine

John Mahler
Special to the Star

Have you ever looked at the tires on your child's school mini-bus? I haven't either.

Three New Brunswick women have and they didn't like what they saw, and they are very, very angry.

And so am I.

Isabelle Hains, Marcella Kelly and Ana Acevedo all lost sons in the tragic crash of a 15-passenger school van in which seven members of the Bathurst High School basketball team and one teacher died. The school van collided with a transport truck in January 2008.

Probe of N.B. school bus crash urges 24 recommendations

Complete 2009 winter tire guide

The pair lobbied for an inquest, so the results would help ensure this kind of tragedy would never recur. Eventually they succeeded.

One of the many recommendations coming out of the inquest was that all school buses be equipped with winter tires during the winter. The mothers thought they had won an important victory for children's safety.

So imagine their shock last month when they saw that the mini-bus used to transport students to extracurricular activities at Bathurst High School was not fully equipped with winter tires. School District 15 had equipped the bus with Hakkapeliitta winter tires on the dual rear wheels and Michelin LTX all-season (light truck) tires on the front wheels.

"It would appear they haven't learned their lesson," was Hains' reaction.

Isabelle Hains did some research on tires and found out that, to be effective, winter tires are required on all wheels. She checked with experts including Nigel Mortimer of Transport Canada and the Star's Tire Guy – me. We both advised her that, yes, winter tires are required on all wheels for maximum safety.

An easy fix, just notify the board and they'll change the tires, you'd think.

Wrong! The superintendent of the board, John McLaughlin, was quick to reply that the board had met the letter of the law, and quoted a directive from the Ministry of Education that applies to much larger school buses. But the directive that applied to large school buses left a loophole so big you could drive a mini-bus through it.

The board had met the letter of the law while ignoring the intent. Isn't bureaucracy a fine thing. After all, using the loophole saved the Board of District 15 some money by not having to buy new front tires – or did it? In fact, they later did change the front tires of the bus from the Michelin light-truck tires to Goodyear Wranglers – another all-season tire. So there went the savings. Why not buy two winter tires instead? My guess is that bureaucracy doesn't like to be told what to do, especially by mothers.

Transport Canada's Mortimer wrote to the board, pointing out the error. I plied Hains with research material to help her cause. The board politely told Mortimer to mind his own business. Transport Canada has no provincial jurisdiction on the bus tire issue.

I checked with contacts at the tire companies to make sure we were on the correct track.

Michelin North America'sRon Margadonna, senior technical marketing manager, replied: "It is clear that the tire industry recommends winter tires on ALL wheel positions for safe driving in winter conditions.

"However, if a consumer so chooses to only purchase two winter tires (based on a four-wheel- or rear-drive vehicle only), these tires should be installed on the rear axle of the vehicle. This would also apply on a bus.

"In addition, the consumer needs to know that by not installing winter tires on all wheel positions, a traction imbalance results, which can create a vehicle stability issue, especially when cornering or during an emergency manoeuvring or braking scenario."

Toyo Tire's Canadian sales managerJames de Chavez replied: "I spoke with someone from our tech department regarding your inquiry. He advises that the theory is the same for a car as it is for a small bus. Therefore, winter tires need to be on every axle to gain the true benefits received from a winter tire.

"An LT (light truck) metric tire will not achieve what a true winter tire can in snowy conditions, therefore mixing and matching them is not recommended."

The reason is that an LT metric tire will not have the same gripping capabilities as a winter tire. Therefore, if the tires are mixed (i.e. winters on one axle and LT all-seasons on another), then the bus may experience difficulty.

For example, during braking with front all-seasons, "it's possible that the small bus may even spin out of control because of the difference in braking in the snow when compared with a winter tire."

Bridgestone North America's Guy Walenga, director of engineering, commercial product technology, also found the board's decision strange.

"There is more than one answer to this question," he replied. He likened the all-season-on-the-front setup to a large tractor-trailer unit that, in the winter, typically uses winter tires for traction on the drive wheels only, but which is a much different vehicle.

"A front rib tire setup may be okay for a pro driver," he said. "On the mini-bus, is this the best setup? No. In braking on snow, when weight transfers forward, winters on the front will stop better than all-seasons. In a corner when grip is lost, understeer is the best of a bad situation.

"An all-season will slide sooner in corners – lose grip – than a winter tire. Then as speed scrubs off, the winter tire will regain grip faster, sooner. On ice, it is a toss-up.

"Most importantly, drivers need to be trained," he continued. "They must slow down for conditions, no matter what the vehicle. The most common mistake is driving too fast for conditions."

Walenga offered the example of the worst case scenario: "The driver is enroute, it starts snowing, the driver has a headache, the kids are screaming in back – two winter tires on front are better than Excedrin. For non-pro drivers, winter tires on the front will give a driver more confidence. Confidence makes for a better driver."

So it is clear that four winter tires on a bus – or any vehicle for that matter – make a profound difference. Vehicle braking capability is affected by the imbalance of winter and all-season tires mounted at the same time on the same vehicle. Tire experts have come to this conclusion, and it's not just because they want to sell more tires. There is serious technology involved in these product decisions and the tires have been created to act in tandem back and front.

It's a no-brainer these days to understand this premise.

To check on the vehicle dynamics aspect of the mini-bus, I consulted Malcolm Elston, a very experienced high-performance driving instructor. In addition to teaching the fine art of going fast the right way for the last 15 years, Elston is also a certified licensed driving instructor in Ontario.

"It is well-understood and documented that the traction capability of a summer-rated tire is adversely affected as ambient temperatures drop below 7 degrees Celsius," said Elston, "just as it is well recognized (and provable) that winter tires can be engineered to deliver traction capability down to minus 40 degrees.

"Having said that, I cannot cite any knowledgeable source that recommends mixing summer-season temperature range tires with winter-season temperature range tires on the same vehicle, at the same time. To equip a child-carrying bus in such a manner is, in my opinion, misanthropic.

"If a driver brakes hard whilst in the middle of a turn, or suddenly swerves to make an avoidance manoeuvre while braking hard, vehicle dynamics can be a key contributor to the driver giving up control of his vehicle, and spinning or crashing it.

"A sudden transfer of weight longitudinally (along the length of the vehicle) occurs under hard braking, as noted. Put another way, that means there is now less weight on the rear tires. A sudden steering input while braking hard will dynamically transfer weight from side-to-side, greatly increasing the probability that the rear tires will slide sideways."

So in the end, I have not found anyone who would endorse the all-season tires on the front of Bathurst School District 15's mini-buses.

I am saddened by the "we know what's best for you" attitude of the bureaucrats. I am depressed by the nit-picking "letter of the law" pro-forma actions of the school district, which ignores the intent of the law.

The policy is just plain wrong.

Related links:

Probe of N.B. school bus crash urges 24 recommendations

Complete 2009 winter tire guide