On May 21, 1901, the Motor Car Act 1903 was not yet in force, but the year 1901 marks a period when Britain and other countries began formalizing rules for motor vehicles. The event commonly referenced as the imposition of the first automobile speed limit refers to early local and national efforts around the turn of the 20th century to control emerging motor traffic. In Britain, the gradual replacement of the restrictive Locomotive Acts (the “Red Flag” laws) culminated in legislative change that recognized motor cars and introduced statutory speed controls and vehicle registration. Background Through the late 19th century, steam-powered and later petrol-driven vehicles operated under a patchwork of regulations. The Locomotive Act of 1865 required a man walking ahead of a vehicle with a red flag and set very low speed limits (2–4 mph), reflecting concerns about safety and the protection of horses and pedestrians. These measures effectively hindered the early adoption and development of motor vehicles. Rising technical improvements and pressure from automobile advocates led to political reconsideration by the turn of the century. Legal change and the 1901–1903 reforms Efforts to modernize regulation accelerated around 1901. Local authorities and early motor associations began to push for reasonable limits and recognition of motor cars as distinct from earlier “locomotives.” Parliamentary debates and committees examined how to balance public safety with technological progress. The key legislative milestone that supplanted the old regime was the Motor Car Act 1903 (passed in 1903 and coming into force thereafter), which introduced vehicle registration, driver licensing, and a national speed limit of 20 mph for motorcars on public roads in Great Britain. Why May 21, 1901 is noted May 21, 1901 is sometimes cited in timelines as a marker in the transitional period when authorities began imposing speed limits specific to automobiles or when local bylaws addressing motor traffic were recorded. While the definitive national 20 mph limit is most directly tied to the Motor Car Act 1903, the years immediately preceding it—including 1901—saw growing municipal and legislative activity that laid the groundwork for the 1903 statute. Impact and significance The establishment of a clear statutory speed limit and vehicle registration framed motorcars as a regulated form of transport rather than experimental or exceptional machines. The 20 mph limit in 1903 represented a compromise: markedly higher than the old red-flag limits, yet cautious by modern standards. It enabled safer integration of motor vehicles into public life while addressing public concerns. These early regulations also set precedents for licensing, insurance expectations, and road safety policy that would evolve throughout the 20th century. Historiographical note Accounts vary in how they date the "first" automobile speed limit because different jurisdictions and local councils enacted their own rules at different times, and Britain’s transition involved several statutes. The clear national speed limit most historians attribute to the Motor Car Act 1903; earlier dates such as 1901 reflect important steps and local regulations in the broader regulatory transition rather than a single, universally applied national law enacted on that exact day. Conclusion The early 1900s were a formative period for motor-vehicle regulation. May 21, 1901 sits within that period of change: a date tied to the wider movement that led to the formal imposition of a national speed limit and other regulatory measures by 1903. These measures shaped the legal framework for motoring and public safety as automobiles moved from novelty toward mainstream transport.