DEPARTMENT OF TRANSPORTATION

                   BUREAU OF HIGHWAY TECHNICAL SERVICES

                             TRACTION DEVICES


(By authority conferred upon the department by section 710 of Act  No. 300 of 
the Public Acts of 1949, as  amended,  being   S257.710   of   the   Michigan 
Compiled Laws)


R  247.171   Definitions.
  Rule 1. (1) "Reference standard studded tire" means size  E  78-14,  4-ply, 
bias construction tubeless snow tire containing 90  studs  (kennametal  class 
III (16-3-585)) fixed in 6 rows around the tire with 15 studs in each row.
This reference tire was chosen because it was that used in  the  wear   tests 
reported in laboratory evaluation of pavement  damage   caused   by   studded 
tires, salt, and  abrasive  sand,  final  report,   American   oil   company, 
project 6128, May 1971.
  (2) "Bias construction tire" means a pneumatic tire  in   which   the   ply 
cords extending to the beads are laid at   alternate   angles   substantially 
less than 90 degrees to the centerline of the tread.
  (3)  "Northern  Lower  Peninsula"  means  all   counties   whose   southern 
boundaries are as far or farther  north  than  the   southern   boundary   of 
Missaukee county.

  History:  1979 AC.


R  247.172   Applicability.
  Rule 2. (1) These rules apply to all public streets and  highways  in  this 
state.
  (2) These rules do not prevent the application of any  other   statute   or 
local ordinance which is  more  restrictive  than   these   rules.   Traction 
devices shall not  be  used  pursuant  to  these  rules   unless   there   is 
compliance with other laws and ordinances.

  History:  1979 AC.


R  247.173   Restrictions on use.
  Rule 3. After March 31, 1975, a  vehicle  or   special   mobile   equipment 
shall not be operated on the public streets or highways of  this   state   on 
metal or plastic track or on tires which  are  equipped   with   metal   that 
comes in contact with the surface of the road  or  which   have   a   partial 
contact of metal or plastic with  the  surface  of  the   road,   except   as 
provided in section 710 of Act No. 300 of the  Public  Acts   of   1949,   as 
amended, being S257.710 of the  Michigan  Compiled  Laws,   or   unless   the 
device meets the requirements set forth in these rules.

  History:  1979 AC.


R  247.174   Use of traction devices.
  Rule 4. Studs or other traction devices shall not be   used   unless   they 
wear either concrete or asphalt pavements, typical of those in this state, at 
a rate not to exceed 25% of the reference standard studded tire.

  History:  1979 AC.


R  247.175   Seasonal restrictions.
  Rule 5. Traction devices permitted under these rules may   be   used   only 
between November 15 and April 1 of the succeeding year except  in  the  Upper 
Peninsula and the northern Lower  Peninsula,  where,   because   of   extreme 
winter snow and ice conditions, they may be  used  between   October  1   and 
May 1 of the succeeding year.

  History:  1979 AC.