How the 341M Spec Benefits Municipal Asphalt Paving

Table of Contents

• The Current State of Texas Municipal Asphalt Paving
• Breaking Down the 341M Spec
• How Else Does the 341M Spec Benefit Local Agencies?
• What If I Only Want To Adopt A Portion of the 341M Spec?

“341M? Don’t you mean 341?”

This is a common reaction when the topic of TXAPA’s 341M specification comes up, and it’s exactly why the spec exists. While TxDOT’s 341 spec is a go-to for Texas road construction, municipal asphalt paving presents a different set of challenges and realities. 

In May 2024, TXAPA’s 341M specification was approved for use, and we’re here to explain how it differs from the 341 spec and why it benefits road construction in Texas cities and counties.

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The Current State of Texas Municipal Asphalt Paving

The Texas Department of Transportation (TxDOT)’s 341 specification is a common dense-graded asphalt mixture used by many cities and counties on their roadways. However, Texas is a diverse state with distinctive regional source materials, and city and county specs can greatly vary as a result.

Additionally, cities and counties may be slow to update their specs and end up adhering to guidelines that are a little over 20 (or even 30) years old. A West Texas county may be referencing the 2004 spec book, while a city in the Piney Woods could still be using the 1994 spec book.

As technology advances, following these outdated specs can prevent local agencies from benefiting from improved materials, testing methods and construction practices that ultimately result in better Texas road construction. 

Enter: the 341M specification.

Breaking Down the 341M Spec

TXAPA developed the 341M specification (with “M” standing for “municipal”) as a modernized, flexible specification tailored to the unique needs of Texas cities and counties. While it closely aligns with TxDOT standards, 341M recognizes that local agencies often operate with fewer resources and different acceptance criteria than TxDOT.

For example, many municipalities will take contractors’ quality control test results as their form of acceptance of a project, whether the contracted technicians are certified or not. On a TxDOT job, every test result obtained throughout the course of a project, from mix design to construction sequencing to inspection testing, must be taken by a certified technician.

To help improve pavement quality assurance for local agencies that rely on contractor testing for project acceptance, the 341M spec makes city and county specs more like TxDOT’s and bolsters contractor quality assurance.

When each city and county has different specs, requirements and test protocols, it can also be confusing for producers and pavers working for multiple entities. Every time a mix is changed, the risk of contamination or sending the wrong mix to a project increases.

By encouraging regional consistency, the 341M spec can create a more reliable product and lead to better construction and longer-lasting pavements.

How Else Does the 341M Spec Benefit Local Agencies?

The 341M spec:

• Standardizes mixes across your region, helping lead to better material availability and normalized costs
• Supports the use of recycled asphalt pavement (RAP), which balances sustainability with strict pavement quality control 

• Allows TxDOT-approved mixes as appropriate substitutions, so there’s a quicker turnaround for mixes that have already been approved
• Is layer-specific, meaning the spec calls out differences in base, intermediate and surface courses
• Is based on current Superpave Gyratory Compaction for lab-molded densities, not outdated tests
• And more

What If I Only Want To Adopt A Portion of the 341M Spec?

The good news is: 341M isn’t an “all or nothing” kind of spec. The goal of the 341M spec is to mix the best of both worlds—TxDOT specs and municipal specs—to benefit Texas road construction in cities and counties. It’s meant to supplement your current specs, not totally replace them.

As an association committed to education on behalf of the asphalt pavement industry, our team is happy to sit down with you, talk through your current specs and give our opinion on how to best incorporate the 341M specification into your current specs.

Give us a call at (512) 312-5043 to schedule a complimentary consultation with TXAPA today. For more asphalt pavement industry insights, subscribe to our YouTube channel and tune into our newest podcast, Road Maps With Sam & Larry.

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