America's Missing Regulatory Tier: Why Fiat's Quadricycle Exposes a 40-Year Gap

The US lacks a federal vehicle class for small, low-speed machines ubiquitous in Europe and Japan. Fiat's Topolino quadricycle—a 19 mph electric runabout priced under $15,000—enters a regulatory void where kei trucks, NEVs, and LSVs navigate state-by-state rules instead of unified federal standards. This patchwork reflects how NHTSA's framework, designed for cars and motorcycles, never accommodated a middle tier. The void persists precisely because it has no obvious constituency: too slow for highway infrastructure, too car-like for bicycle-shop retail, too niche for automakers to lobby around.