Steer-by-wire replaces the mechanical linkage between the steering wheel and the road wheels with electronic sensors, actuators and a control unit, so the driver's input and the wheel response are connected only by signal, not by a physical shaft. Because the core innovation is the steering mechanism itself, essentially all 308 tracked families classify under B62D, the motor vehicle steering subclass. Secondary classifications in vehicle control, propulsion and braking subclasses show that steer-by-wire is usually claimed alongside broader vehicle control systems rather than as a standalone mechanism.

Filing volume rose from 9 families in 2017 to a peak of 45 in 2021, then held near that level with 36 filings at the 2022 midpoint, which points to a plateau rather than continued acceleration. Publication typically lags actual filing by around 18 months, so the most recent years in any trend understate true activity and should not be read as a collapse. The honest read is that the field grew quickly through the late 2010s and early 2020s and has since stabilized at a steady, if not expanding, filing rate.

The most-cited patents in this corpus, including US6176341B1 on a master/slave steering configuration and US6097286A on steer-by-wire with feedback, date back to the early 2000s and underpin much of the later architecture. These foundational filings established core concepts like fault-tolerant electromechanical actuation and tactile feedback control that recur across later filings from multiple assignees. Because citation counts favour older, longer-searchable records, this list reflects historical influence on the field rather than which company is most active today.

The densest claim coverage sits around core actuator redundancy and basic tactile feedback control, both heavily cited and filed since the early 2000s. Comparatively thinner coverage appears in cross-vehicle fault recovery signalling, redundant power-path failover logic, and integration between steer-by-wire and brake-by-wire arbitration — areas that sit adjacent to the dense core but are not yet saturated in this dataset. A targeted prior-art search in these specific branches, rather than the general steer-by-wire category, is the more productive starting point.

The United States dominates this dataset with 178 of 308 records, more than three times the next largest office, the EPO at 51. WIPO/PCT filings (21), China (20), Germany (16) and the UK (13) follow at meaningfully lower volumes. Any freedom-to-operate review should prioritize US patents first given the concentration of filings there, then extend to the EPO and, depending on target markets, China and Germany.