Why Are Trucks Driving Slower in Michigan This Time of Year?

If you've ever been stuck behind a truck that seems to be poking along, you've probably been frustrated. However, there's a very good explanation why that vehicle is driving significantly slower than the rest of the traffic.

Rest assured, the driver isn't trying to annoy you. I had always assumed that truck drivers were being paid by the hour, so they were taking their sweet time in order to pad the time clock. But we all know what happens when you assume, right?

Why Do Michigan Truck Drivers Drive Slower in the Spring?

If there's one thing we're really good at in Michigan, it's potholes. And you've likely noticed that this year's crop is growing exceptionally well. Attempts to "Fix the damn roads" are - for the most part - futile.

During the spring months, when the ground is saturated and weakened, rules are implemented to help protect Michigan roads from further damage. 'Seasonal Weight Restrictions' (more commonly known as 'Frost Laws')

Michigan Frost Laws Explained

If you've ever been behind a truck traveling 35 miles per hour in a 55 MPH zone, Seasonal Weight Restrictions are likely in effect. According to the County Road Association of Michigan (CRA), these restrictions help "strike a balance" between protecting Michigan roads and conducting business as usual.

Restrictions are placed on roads not designated as "All Season Routes," sometimes called "Class A" roads. Interstates and US routes like I-75 and US 23 as well as Michigan routes (roads that begin with 'M-') are considered Class A roads and not subject to restrictions.

However, trucks on all other roads must adhere to these parameters:

• Axle-load limits are reduced by 35% and
• Travel speed is limited to 35 MPH (regardless of the posted speed) for vehicles over 10,000 pounds.

When Are Seasonal Weight Restrictions Implemented in Michigan?

The timing of these restrictions varies by county, but they're typically implemented in late February or early March as spring weather conditions warrant.

Seasonal Weight Restrictions are typically lifted in late April or early May, when the roadbeds are deemed dry and stable.