MSP

Michigan Weight Laws

Michigan State Police

Commercial Vehicle Enforcement Division

Insp. Randy L. CoplinApril 21, 2015

Topics of Discussion

Introduction

Michigans Weight Law - General

History

Fines

Road Designations

Frost laws (25% and 35%)

Questions

Introduction

The laws restricting the size and weight of commercial

motor vehicles are complex and require special training.

Michigan has some very unique size and weight laws,

with some of the largest and heaviest vehicles in North

America.

Michigan Weight Law

There are some basic precepts on which Michigans weight law is based:

Michigan is an axle state (no gross weight limit in the statute).

The federal government mandated the use of the Bridge Formula.

Michigans weight law was grandfathered. (Part of the restrictions to the grandfather clause is the maximum allowable axle gross

weight is limited to 164,000 lbs).

Because Michigan is an axle state, there is no legal

definition of misload.

The term is not defined anywhere in Michigan law.

Any amount of overage on an axle is subject to penalty.

Overweight fines are significant.

Even a small overweight creates a fine in excess of most misdemeanors and even some felonies.

Most carriers and owners cited for overweight dont argue that they werent overweight, but argue the amount of the fine.

History Prior to 1952, the fine for weight violations was a simple

misdemeanor, $100 and/or 90 days, regardless of the

amount of overload.

It was much more profitable to run overweight and take the ticket

than to run legal.

1952: the weight law was changed to a graduated scale

penalty.

1968: weight law was amended to read that the court

has discretion as to the amount of the fine if the vehicle is

operated under its maximum allowable weight, the court

may charge $250 in lieu of using the graduated fine scale

History Cont.

1978: weight law was amended, changing the violation

from a misdemeanor to a civil infraction.

1989: the civil infraction penalty was increased by 50%,

the first such change since 1952 when the graduated

scale was established.

Fines for Overweight Axles

Pennies per pound for excess weight:

0 - 1000 = No fine

1001 - 2000 = .03 for every pound over

2001 - 3000 = .06 for every pound over

3001 - 4000 = .09 for every pound over

4001 - 5000 = .12 for every pound over

5001 - 10,000 = .15 for every pound over

10,001 & over = .20 for every pound

Protect Infrastructure

Bridges & Roads

Protect Motoring Public

Unsafe Overweight Trucks

Reduce Repair Costs

Heavy Trucks Damage Roads

Save Lives

Traffic Crashes/Deaths

Reasons for Laws and Enforcement

Axle Weights General Information

Maximum load limits may depend on the following: Type of highway you are operating on.

The number of axles and the distance (spacing) between the axles or axle assemblies on the vehicle or combination of vehicles.

The maximum allowable gross weight of the vehicle or combination of vehicles.

Tire width (as published by the manufacturer).

Depending on the conditions above, your vehicle may be subject to the maximums found under the normal loading, designated loading,

or special designated loading standards.

Road Designations

Normal Loading

Designated Highway

Special Designated Highway

Terms

Normal Loading Maximum is the basis for all roads

within Michigan.

Found in Subsection (1).

All vehicles get at least these weights, unless posted at

lower weights.

Normal Loading Maximums

18,000 lbs., provided the axle has a 9 foot spacing on

EACH side.

13,000 lbs., provided the axle spacing is between 3

feet and 9 feet on EITHER side.

9,000 lbs., provided the axle spacing is less than 3

feet on either side.

Designated HighwaysExtension of Normal Loading

Designated highways build from Subsection (1).

Found in Subsections (2) and (3).

Road must be Designated by agency (state or local)

having jurisdiction.

Designated Loading Maximums

One Tandem Axle Assembly may have a gross weight of 16,000 lbs. per axle, provided that there is

no other axle within 9 feet.

No other tandem exceeds 13,000 lbs. per axle.

5-Axle Truck Tractor-Semi Trailer (Tandem-Tandem) Combination:

(Two Tandem Axle Assemblies at 16,000 lbs. per axle).

Special Designated Highways

Special Designated highways are based on the Bridge

Formula.

Found in Subsection (12) and is based on Federal

Regulations.

Applies to all Interstate freeways, US, and most M

Routes.

Road must be Special Designated by agency (state or

local) having jurisdiction.

Special Designated Highway

Maximums

20,000 lbs. on any 1 axle;

A tandem axle weight of 34,000 lbs.;

All other axle combinations depend upon the Bridge

Formula. There may be several axle groups on any

given vehicle or vehicle combination.

Frost Law

By statute, reduced weights are in effect during March,

April, and May.

The maximum axle load allowable on concrete

pavements or pavements with a concrete base is

reduced by 25%, and the maximum axle loads allowable

on all other types of roads during these months are

reduced by 35% from the maximum axle loads as

specified.

Weight restrictions may suspend or implement when

determine necessary.

Width, Length and Height

Height legal 13 feet

Width total outside body width of a bus, a trailer coach, a trailer, a semi trailer, a truck camper, or a motor home

shall not exceed 102 inches.

The total outside width of the load of a vehicle hauling concrete pipe, ferrous pipe, agricultural products, or

unprocessed logs, pulpwood, or wood bolts shall not

exceed 108 inches.

Length vehicle and route specific

Portable Scales

Stationary Scales

Questions