by Jeff Tuzik Vehicle stability is of paramount concern in the rail transit environment. It affects safety, ride quality, and wear and damage on the track, wheels, trucks, and suspension. In turn, stability is largely defined by the interplay of track characteristics, wheel and rail profiles, and truck and suspension …
By Jeff Tuzik Autonomous track inspection technologies play a large and growing role in the maintenance and monitoring strategies of freight railroads in North America. While the technologies are relatively new, they have already evolved, along with the goals and overall capabilities of track inspection. On Canadian National, Automated Track …
by Jeff Tuzik (This article was previously published in the December 2025 issue of Mass Transit) One of the most vexing, and increasingly common rail defects that rail transit agencies contend with is the squat-type defect (stud). Addressing studs has been challenging in that they are not fully understood, and, …
by Jeff Tuzik Understanding and improving wheel/rail interaction requires unwavering attention to the little details that can have a big effect. It’s what we do here at Interface Journal and what we talk about at the annual Wheel/Rail Interaction conferences that we participate in. But every now and then, it’s …
by Jeff Tuzik The L/V ratio is a ubiquitous measurement in the world of wheel/rail interaction. It is typically combined with the Nadal limit, functioning as shorthand for wheel climb derailment risk for a given set of conditions. But the L/V ratio and the various formulae used to set risk …
by Jeff Tuzik Rail transit systems collect a lot of data. This is data collected from many sources—wheels, rail, track, and vehicles—and from many types of measurement devices. Some of the data must be collected per regulatory requirements, but much of it is collected because it’s valuable. Transit systems use …
by Jeff Tuzik What do 30 years of advances in wheel/rail interaction look like? Thirty years ago, the field of wheel/rail and vehicle/track interaction was largely unknown outside a coterie of specialists and researchers. Railroads operated within confined departmental siloes with vehicles on one side of the ledger, track on …
by Jeff Tuzik Track condition is about more than rails and ties. It includes everything below the rail and ties, too. Track components, ballast, and subgrade are all part of the package; they all affect overall track condition. And, as Brazil’s MRS Logística’s track renewal programs have shown, improving track …
by Jeff Tuzik The benefits of friction management are well known and often touted. But one benefit in particular—fuel savings—receives far less attention than the others. But as railroads race to meet greenhouse gas reduction targets and ultimately net-zero goals that they have set for themselves, fuel savings have become …
By Jeff Tuzik Friction modifiers—whether gage-face lubricants (greases) or top-of-rail (TOR) friction modifiers (FM)—are a well-established, and indeed, a common part of the wheel/rail optimization toolkit. In the railroader’s mind, these technologies tend to be associated with wayside application equipment and installations, but vehicle-mounted wheel-flange lubricators and wheel-tread friction modifiers …