May 31, 2018


For years, truck drivers have been able to get weigh station bypasses based on the strength of their carriers’ safety records. Transponders, such as those offered by PrePass® and NORPASS offered the only way to bypass weigh stations. They worked much like those in an automated toll paying system or an anti-theft inventory control device that allows retail stores to track inventory and dissuade shoplifting.

In July of 2013, the Federal Motor Carrier and Safety Administration (FMCSA) announced that network devices such as smartphones and tablets using commercial mobile radio service or CMRS technology — the same technology that delivers cell phone calls — could be used as transponders for weigh station bypass. Since then, the number of locations providing opportunities for weigh station bypass using smart phones, tablets, and electronic logging devices (ELDs) has nearly quadrupled from just over 200 to 720 in 43 states and provinces.

At no time in its history has the trucking industry had as many opportunities for weigh station bypass as it does today with CMRS technology. That’s why it’s important for drivers and fleet managers to fully understand the differences between the two available technologies so they can make informed choices.

That ‘70s Show – Technological differences between CMRS and RFID

First, it’s important to understand how each technology works. A transponder-based or radio-frequency identification (RFID) system employs roadside sensors that generate electromagnetic fields to automatically identify and track the transponder. RFID has been around since the 1970s.

Individual states or their transponder-based weigh station bypass providers set up transponder readers on the sides of roads or at weigh stations to provide bypasses by scanning the RFID transponders as the trucks pass beneath them. Depending on the number of locations, this infrastructure can cost millions of dollars to bring online in just one state. Costs include putting up the required transponder-reader poles at each site, as well as their ongoing maintenance. This not only makes transponder-based bypass more expensive than CRMS, but it also means that it can take a lot longer to get every single bypass site up and running. Expanding network coverage on a transponder-based system is often a slow and tedious process.

Since CMRS bypass technology uses existing GPS and cellular service network to transform mobile devices into ‘smart transponders,’ weigh station bypass can be set up quickly. Currently, there is only one existing CMRS-based bypass program — Drivewyze PreClear, which is at the heart of the Omnitracs Weigh Station Bypass service.

Geofencing makes more rapid deployment possible

To establish weigh station bypass, Drivewyze employs GPS technology to create virtual geographic boundaries around weigh stations. This is otherwise known as geofencing. When a mobile device or ELD with the Drivewyze application running enters or leaves one of those weigh stations, the application makes note of the time and location of the visit and the length of time the truck spends at that location. Drivewyze has set up geofences around every weigh station in the United States and some in Canada. Compared to setting up transponder-based bypass at a particular location, it takes very little time to set up Drivewyze service at a weigh station. This allows Drivewyze to grow and expand into multiple bypass sites in a fraction of the time it takes to establish transponder-based service. In many cases, geofencing allows weigh station bypass to be offered for the first time at mobile/temporary inspection sites.

The driver experience

To obtain bypasses using a transponder-based system, drivers must often merge into the right lane to drive under the transponder-reader pole, located about a mile away from the station. The transponders then let drivers know if they received bypass through auditory and visual cues. A small green light signals to drivers that they can bypass the stations, while a small red light signals drivers to pull in.

Unlike with a transponder-based system, drivers can receive bypasses regardless which lane they are in when using CMRS-based bypass. This means drivers don’t need to make any sudden lane changes. Two miles away from the station, drivers receive notification that lets them know of an approaching active weigh station. Within one mile of the station, another notification gives drivers plenty of time to safely move into the right lane if necessary. This can significantly reduce the risk of drivers accidently driving past weigh scales.

When drivers receive bypasses, their mobile (or telematics/ELD) devices display a large green ‘Bypass’ sign on the screen and play an audible signal. If the driver must pull into the station, Drivewyze will play a different audible signal, and show a screen that says ‘Pull in Unless Closed.’ With Drivewyze, drivers can easily review bypass instructions by simply clicking on a recall button. A transponder-based system flashes red or green for only up to 15 minutes after the driver passes the weigh station. This limited function can make it difficult for drivers to show enforcement officers past weigh station bypass instructions upon demand.

WIM integration

While integrating CMRS-based bypass with weigh-in-motion (WIM) scales proved to be a challenge years ago, recent improvements in both cellular data network speeds and GPS client software have largely overcome that challenge. Today, CMRS-based bypass has joined transponder-based bypass in successfully integrating with WIM scales, and providing bypasses at WIM sites — with five such locations in Idaho recently added to the Drivewyze network. To date, Drivewyze has successfully integrated with WIM scales at more than 100 locations throughout the United States.

Inventory requirements

When using transponder-based bypass, most fleets must manage significant inventories of devices. Considering the transponders’ small size, which makes them susceptible to loss or theft, and the fact that replacements can cost $100 each, fleets often find maintaining those inventories time-consuming and expensive.

Because CMRS bypass is integrated into mobile and telematics devices, there is no additional hardware to manage. This means that fleets using CMRS bypass, like Drivewyze, don’t need to worry about inventory management, lost/stolen transponders, or any additional costs. There’s no additional inventory required; fleets can add trucks to the program or take trucks out as needed. Carriers that have chosen to deploy Omnitracs can receive even more of a return on their investment, by using the equipment they’ve already installed to deliver bypasses to their drivers.

Reporting and business intelligence for fleets

Transponders are limited in terms of the data they can collect. Most transponder-based bypass services only provide basic reporting to fleets, such as the number of bypasses received each month.

Using its aforementioned geofencing capability, technology like Drivewyze can provide fleets with sophisticated, GPS-based reporting. This means fleets can get more data than just the number of bypasses received. For example, Drivewyze reporting can show carriers how much driver time is wasted at all weigh stations and inspection sites across the United States, not just at Drivewyze-enabled sites. The data shows you where your trucks are being pulled in the most, and for exactly how long.

Choosing the right bypass technology for your fleet

There are many things to consider when selecting a bypass service for yourself, or for your fleet. The type of technology (and what value it can provide) is certainly one important criterion to consider. Service coverage or the number of participating states and sites as well as customer service are two other important considerations. So, when you’re trying to decide which service is best, do your homework — call the bypass services you’re interested in, ask questions, ask for a free trial, and get driver feedback whenever possible.

To learn more about Omnitracs Weigh Station Bypass provided by Drivewyze PreClear, visit the solution page or contact Omnitracs.

PrePass® is a registered trademark of HELP Inc. in the United States and/or other countries. All company, product, and service names used in this document are for identification purposes only. Use of these names, trademarks, and brands does not imply endorsement.