Your internal rules are optimized for optimally set speed limits (85th-90th percentile speed when no speed limit exists, then narrow minimums and maximums stric

Your internal rules are optimized for optimally set speed limits (85th-90th percentile speed when no speed limit exists, then narrow minimums and maximums strictly enforced.) Most speed limits in the US are set artificially low for the quality of the road. This creates dangerous differences in speed among drivers. Enforcing left lane passing mitigates the risk by keeping passing orderly. Drivers enforcing the maximum speed limit in the left lane prevent orderly passing. On top of the behavioral issue, there are legitimate reasons for non-emergency vehicles to overtake vehicles. I don’t expect you to agree with this, but it is a majority view so preventing it is anti-social (though not as much as blocking driving on the shoulder, which is extreme behavior committed for reasons similar to principled left-lane occupation.) Roads with fewer lanes require more adherence to social customs than wide roads to keep them safe and effective. Most don’t require an elaborate explanation as they can intuitively sense the benefit of staying in the right lane when not passing, as they gain experience with a wider variety of traffic situations.