The benefits to society of legalized lane-sharing - the California Vehicle Code has a good model statute defining a legal lane-sharing practice - are substantial in urban California, where a large motorcyclist population exercises extensive lane-sharing on a daily basis. These are my empirical observations over several decades of riding and observing in the US as well as Southeast Asia. The benefits are:
Added protection from cars rear-ending the motorcyclist in typically tightly-spaced urban traffic patterns; fewer traffic jambs due to such accident scenes; lessened impact to vehicle & disability insurance claims patterns; fewer lost work-days due to typically severe injuries to the motorcyclist from such accidents.
Eased traffic congestion, as the motorcycle traffic effectively disappears from the dual track vehicles' flow pattern - which defines the overall flow of traffic. As more motorcycle miles are driven each year, this benefit of motorcycles to society will only increase. One need only review countries such as Vietnam or Thailand, where if the motorcyclists were constrained from lane-sharing, the result would be a substantial increase in gridlocked traffic.
Lessened air pollution & conservation of fuel due to the above traffic easing; from the cars as the entire flow is sped up by removal of the cyclists from the predominant vehicle flow; from all motor vehicles invoved as increased speed & engine RPM lessens pollution since the engines are running more frequently & for longer periods in their optimum efficiency ranges of operation.
Eased urban on-street parking shortages and less real estate required for car parking; as urban traffic average speeds decrease, more commuters move to motorcycling to substantially decrease their commute times, which lane-sharing substantially assists. Cities where such phenomena have evolved have seen, and in some cases promoted, dedicated motorcycle parking areas to encourage this parking- & traffic-easing practice. Examples of dedicated cycle parking include San Francisco and most Asian cities. Other US & European cities may also have dedicated parking - will fellow members please add these to the thread for the record.
The safety, societal & environmental benefits of legalized lane-sharing need to be documented and widely publicized to assist in gaining support for changes to the laws & ordinances necessary to bring this rational & beneficial practice into full societal acceptance.
Respectfully,
Bruce Bradsby