There should be no level of congestion for some existing lanes.
When there is congestion on a freeway, there is incentive to drive because most likely, it’s faster than traveling by bus. But when there is no congestion (and the only way to guarantee that is to forbid or severely limit private vehicle access), commuting by bus then become much more appealing.
This is the indeed the case with the I-10 busway/carpool lane today. It only takes 15 minutes to travel downtown from El Monte on the Silver Line rapid bus (not exactly BRT since it doesn’t have its own dedicated lane) while driving would take more than 40 minutes. People living in all parts of the San Gabriel Valley drive (oh well) to El Monte to ride the Silver Line. There is a bus every 10 minutes during peak hours and each vehicle is filled to capacity.
It seems the problem of cars crowding the HOV lane has been solved; I assume this is due to the success of the current restrictions. The newer rule is that at least three passengers (instead of only two) must be present in order for a car to travel along the HOV lane during peak hours.
But “creating” a busway generates its own problems. The busway lane along I-10W, and especially the separate grade ROW created parallel to I-10-E, were built after the I-10 itself. The previously four-lane I-10 became a 5-lane highway; why couldn’t it have remained four lanes with an existing lane converted to an HOV lane? Cities are not ready to stop creating and re-enforcing capacity for cars. In an ideal planning world, the I-10 would have three lanes total, with one for buses and one for carpools.
When it comes to surface infrastructure, creating supply only delays and exacerbates the repercussions of the problem.
