MITIGATING HIGHWAY NOISE WITH ADVANCED PAVEMENT TECHNOLOGY

Exploring data on acoustic longevity

A 2009 report published by the American Concrete Pavement Association, "Transportation Noise and Concrete Pavements," remains relevant today with transportation noise continuing to be a critical quality-of-life issue and a primary constraint in highway infrastructure design. Managing acoustic impacts while maintaining project budgets, safety standards and collaborative timelines requires a rigorous evaluation of pavement surface technologies.

The report outlines the mechanics of highway noise, emphasizing that passenger car noise is dominated by tire-pavement interaction, while heavy truck noise is driven by elevated drivetrain and exhaust systems. The data underscores that tire whine is a mechanical artifact of uniform transverse tining rather than an inherent property of concrete itself.

Beyond the explicit findings, a close reading of the data reveals some less obvious insights:

• Concrete's exceptional durability can inadvertently harm its acoustic reputation. The public frequently compares 30-year-old transverse-tined concrete to brand-new asphalt overlays, creating a false equivalence.

• Acoustic longevity is a more critical metric for lifecycle cost control than initial decibel readings immediately following construction. 

The NGCS solution

Recognized as the quietest non-porous concrete pavement surface available, Next Generation Concrete Surface (NGCS) is an advanced pavement texture developed through a collaboration between Purdue University, the Minnesota Department of Transportation, the IGGA and the Portland Cement Association.

By combining diamond grinding and longitudinal grooving, NGCS eliminates the tonal spikes associated with traditional tining. The longitudinal grooves provide substantial macrotexture, creating escape channels for water that significantly reduce hydroplaning and enhance wet-weather safety.

Applications in recent years demonstrate its immense value for project management and cost control. During the I-94 expansion in Minnesota, contractors utilized NGCS as an alternative to constructing traditional noise walls near Locke Lake. This alternative technical concept met stringent noise mitigation requirements while saving capital. Furthermore, maintenance crews report that the NGCS texture retains winter deicing salts

more effectively, reducing material usage and providing an immediate environmental benefit.

The Federal Highway Administration (FHWA) currently restricts specific pavement surface types solely as a permanent noise mitigation strategy due to acoustic degradation over time, requiring agencies to determine the acoustic longevity of the surface before embarking on a quiet pavement strategy. However, the FHWA has allowed the use in quiet pavement pilot programs (QPPP) and state-specific research.

By leveraging data from QPPP and state-specific research initiatives, we can deliver robust, evidence-based findings that demonstrate the durability and sustained noise-reduction capabilities of NGCS. In addition, the IGGA will continue to collaborate with others in the industry to develop standardized methodologies for measuring acoustic performance over time, ensuring compliance with FHWA requirements. We will also keep advocating for the broader adoption of NGCS as a cost-effective, sustainable and reliable solution for noise mitigation in highway infrastructure projects.

To dive deeper into the data and see how NGCS can elevate your next infrastructure project and enhance your ROI, review the NGCS fact sheet here: https://ow.ly/1aQp50YQLES