On the 400 series HOV lanes, by the time you factor in safe following distances, a motorcycle is almost the same as a single-occupant car in terms of the space it consumes on the highway.
Of course this makes sense, but whether everyone agrees or not, there is also a valid argument that the lanes could be safer for motorcyclists.
Many of us feel safer in the left lane because there's no traffic on one side. Technically, we're not supposed to drive/ride in the left lane because it's the passing lane - so someone who wants to ride right around the speed limit can't safely do that in the left lane. A rider is limited to a central lane with traffic on either side, or the right lane where there is the most entry/exit turbulence, and increased risk.
On a limited access highway with a lane designated as a limited access lane, at least the RULES EXIST to provide additional protection. The argument isn't about whether every motorist will follow the rules, or what kind of other morons are out there to put as at risk, the argument is about the design and the rules that are created to have a controlled/limited access lane running parallel to traffic, and used only by designated vehicles. Even if the safety proposition turns out not to be supported by statistics, the argument remains untested in Ontario, and the government unwilling to consider it. The argument that it will slow down other vehicles that are currently entitled is a poor one. Motorcycles represent less than 3% of registered vehicles in all of Ontario. Imagine the percentage that are used for riding in rush hour. Even if it doubles because of the opportunity to ride in the designated lane, it's going to be statistically insignificant. Besides, we hear so often that the HOV lanes are nearly empty and the surrounding lanes are packed. If someone does believe the number will be sufficient to have an effect on traffic flow, let's take another class of vehicle out of the congested side and make more space.
The Pan-Am games were a perfect opportunity for the province to test it, by allowing it on a temporary basis in the middle of the riding season. The greater issue, shared by some on this board, is that people won't look past the idea that it's an argument for privilege, not safety.
Where permanent HOV lanes already exist, allowing motorcyclists to use them should have a negligible impact on other HOV users, if at all. There is an unproven, but potential safety benefit to be recognized for motorcyclists. With a stated mandate to review all options to improve road safety for ALL users, it's irresponsible not to consider it, at least on a trial basis.