<p>Speeding heightens the risk of traffic accidents, which are a leading cause of death. Vehicles can be fitted with a new technology, Limited Intelligent Speed Assistants (LISA), that makes it impossible for drivers to exceed local speed limits. In a chapter in Thomas Søbirk Petersen’s recent book, he argues—alongside Kasper Lippert-Rasmussen, who coauthored the chapter—that LISA-enabled vehicles should be mandatory. The authors base their argument on the “Principle of Required Prohibition,” according to which the state ought to regulate design of a product to reduce the harms of illegal use if it can do so without creating comparable harms or making any lawful use impossible, and if this is the most feasible and efficient way to avoid the harm caused by illegal use (Petersen and Lippert-Rasmussen 2025). In this commentary we argue that, at least in some contexts, required LISA installation represents unjustified state action because it undermines moral agency. We understand moral agency as the ability to be sensitive to and act in accordance with our own reasons, including moral reasons. States often use technology to encourage good action and reduce harm by way of our reasoning capacity, by highlighting certain reasons and adding consequences to action. However, LISA technology operates outside of the space of reasons. By removing opportunities for moral choice, LISA can erode moral knowledge and our attentiveness to morally relevant facts. In this way it goes beyond criminalization of conduct, which disincentivizes, but does not make impossible, criminal action. We conclude that LISA is not the most efficient way for a state to reduce the harm related to traffic accidents, at least in certain contexts. We recommend other state actions, including other techno-regulations, that address the harms of speeding without diminishing moral agency.</p>