Setting the Standard: NMi’s Certification of Weighing in Motion Systems

In the transportation and logistics industries, Weigh-In-Motion (WIM) systems have become indispensable for monitoring vehicle weights dynamically as trucks and other heavy vehicles travel over sensors at high speeds. Unlike traditional static scales, WIM systems capture real-time weight data, minimising traffic disruptions and enabling continuous monitoring on busy roadways. This advancement is critical for road safety, regulatory compliance, and infrastructure maintenance—particularly as vehicle volumes and axle weights continue to increase.

Why WIM Needs Unified Standards

Despite its potential, WIM technology has long been hindered by fragmented standards worldwide. A recent NMi poll of industry professionals confirms this challenge, with 56% identifying unified testing protocols as the most critical barrier to overcome. Current standards, like Europe’s COST-323, OIML R134, and the U.S.’s ASTM E1318-09, often address specific regional needs but fail to create a cohesive framework for global interoperability.

The result? Complex certification processes, inconsistent accuracy, and limited trust in WIM systems across borders. With unified standards, enforcement becomes reliable, undermining the full potential of this powerful technology.

A Unified Standard Built for Global Adoption

In response to these challenges, NMi Certin B.V. developed a global WIM standard in 2016, providing the unified testing framework that stakeholders identified as critical to advancing WIM enforcement. NMi’s approach integrates the core elements of existing standards, such as ASTM, COST-323, and OIML R134, into a rigorous certification protocol designed to meet legal and operational requirements for dynamic weighing.

The NMi standard focuses on precision and reliability, with strict testing methodologies for high-speed and low-speed WIM systems. NMi ensures systems are ready for direct enforcement applications by prioritising accuracy across varying speeds and environmental conditions. These unified testing protocols reduce regional disparities and enable systems certified under NMi to be recognised across borders—fostering trust and adoption on a global scale.

Why Unified Testing Protocols Matter More Than Ever

The industry poll highlights that unified testing protocols are the backbone of effective WIM enforcement. Here’s why:

• Streamlining Certification Processes: Unified protocols reduce redundancy, allowing manufacturers to certify products faster and at lower costs
• Building Global Trust: With consistent testing standards, WIM systems gain credibility, fostering broader adoption across regions
• Improving Enforcement Accuracy: Legal enforcement depends on precision. NMi’s rigorous protocols ensure that systems deliver reliable, court-defensible data—even at high speeds

Real-world success stories, such as New York City’s adoption of NMi-certified WIM systems on the Brooklyn-Queens Expressway, show how reliable enforcement can reduce overweight violations and enhance road safety.

Evolving WIM Technology with Unified Standards

As WIM technology evolves, so does the need for smarter solutions. NMi is leading the way by updating its standards to accommodate innovations like sensor fusion and Big Data analytics. These advancements will enable transportation planners to optimise traffic flow, extend pavement life, and manage urban access for heavy vehicles.

What’s Next for WIM Technology

• Smarter Testing Standards: NMi is refining its protocols to integrate advanced technologies, ensuring greater accuracy and adaptability.
• Supporting Smart City Goals: WIM data will play a key role in intelligent transportation systems (ITS), helping cities manage traffic and protect infrastructure more effectively.
• Global Collaboration for Legal Alignment: NMi is working closely with international regulatory bodies to create a unified legal framework for WIM enforcement, paving the way for worldwide adoption.