Each lane on a 400 series should have it's own separate min and max speed limits. Right lane min 90, max 110. Middle lane min 110, max 130. Left lane min 130, max 150 (or more). This would eliminate a lot of congestion and be much safer. You would never pass on the right because traffic would always be slower there, also if an emergency brake and avoid were needed you would always brake and avoid to the right because there wouldn't be anyone flying up the right side of you. As it stands you can get on the 401 in Windsor and drive all the way to Quebec legally in someone's blind spot. Also, I virtually never have someone driving right on my *** because...well...I speed, but if there is someone closing the gap I get out of their way (more than happy to have a speeding ticket lightning rod). That said, I would rather someone close to my tail than right beside me. In an emergency you have 3 options: brake, avoid, or brake and avoid. If someone is right beside you, you're left with only brake (this of course assumes throttling it out isn't an option).
Just my humble opinion.
Just my humble opinion.