Here is the email sent to GoodYear on November 24 2009 by Gary Spencer of the NB Department of Transportation seeking Goodyear's opinion on the use of winter tires.
You will note the following in his letter to Goodyear:
1. The Multi Function Activity Vehicles (MFAVs) have been variously called "small school buses" "20 passenger buses" "passenger buses" and "bus" even though they are not a "bus".
2. Mr. Spencer admits that the MFAV is a new vehicle in the provincial fleet and because they didn't have a policy per se, they simply implemented the tire policy for yellow school buses (even though this is not a bus).
"This size of bus had not previously been utilized in our fleet and our standard school bus tire policy was applied, that is ribbed/steering tires on the steering axle and winter or traction tires on the drive axle."
From: Spencer, Gary (DOT/MDT)
Sent: Tuesday, November 24, 2009 4:13 PM
Subject: Opinion regarding the usage of winter tires on steering axles of small school buses.
Thank you for contacting me to offer your assistance in the selection of the safest tire options for our 20 passenger buses. As a tire manufacturer we appreciate and value your opinion on such matters.
Recently the Province of New Brunswick has taken ownership of some twenty passenger buses which are rear wheel drive construction utilizing one ton chassis'. This size of bus had not previously been utilized in our fleet and our standard school bus tire policy was applied, that is ribbed/steering tires on the steering axle and winter or traction tires on the drive axle. Recently some individuals and tire manufacturers have suggested that RAC certified winter tires should be utilized on all axles as these buses have 16" wheels and "winter" tires are available in that size.
These buses travel as "inter-city" buses, that is, the vast majority of travel will be from one city to another, on highway, with minimal urban travel. The policy for utilization of these buses is such that travel during inclement weather is prohibited. With that said, some travel during snowfall will inevitable occur.
The province has retained the services of an independent Automotive Engineer to provide advise to us on this very important matter. I have attached his report for your review. In summary, Mr. Hoar recommends that on rear wheel drive vehicles we should maintain rear axle traction dominance by installing traction/winter tires on the drive/rear axle and ribbed tires on the front/steering axle. His contention is that rear wheel drive vehicles equipped with traction/steering tires and traveling at highway speeds inherently reduce the risk of oversteer loss of directional stability, and allow the driver a better chance of maintaining or recovering directional control in a evasive or corrective action.
I would appreciate receiving your written opinion regarding the safest tire set-up for these buses. Please feel free to contact me for additional information at (506) 453-2601
Your timely response would be very much appreciated.
Gary Spencer, P. Eng.
Asst Director Operations
Vehicle Management Agency
(See Attached David Hoar's Motion Design Report)
For the full text of David Hoar's letter, click here