This situation happened already with vehicles. California used to get special cars because of their strict emissions regulations. Now every car has "50 state legal" emissions because A) more states signed onto the California standards, B) it was cheaper to build one vehicle to the strictest standards than to make two for a single market.
What's the point in running a diesel semi when it can't be used to make deliveries to key states in the country? That will force a "relay" model in the freight industry which kills point-to-point delivery, where diesels deliver to a border state and an EV semis runs the last leg. Once that happens, then it becomes economical to run more EV semis between diesel relays, or add rail depots to the relays for ultra-low cost transport over long distances, then EVs for the last leg.
The diesel truck industry is going to die slowly, then all at once.
What's the point in running a diesel semi when it can't be used to make deliveries to key states in the country? That will force a "relay" model in the freight industry which kills point-to-point delivery, where diesels deliver to a border state and an EV semis runs the last leg. Once that happens, then it becomes economical to run more EV semis between diesel relays, or add rail depots to the relays for ultra-low cost transport over long distances, then EVs for the last leg.
The diesel truck industry is going to die slowly, then all at once.