> That's because you're taking away space (i.e. making driving worse) in a way which is incredibly inefficient. You have an entire lane dedicated to a bus that only travels in it a dozen times a day.
It's more efficient, not less. Bus lanes don't get built for buses that only have 12 trips a day. They're typically for places that have 10 minute frequencies or better. At 10 minute frequencies, with standard 40 foot buses, the lane capacity is about equal. With 2 minute frequencies, a single bus lane has a capacity about four regular lanes.
Under peak loads, during rush hour, that lane is worth every second of inconvenience to drivers. If they would rather have an extra lane and 3,000 additional drivers on the road, they'll regret it.
> At 10 minute frequencies, with standard 40 foot buses, the lane capacity is about equal.
At 10 minute intervals at 40 MPH, you have 35200 feet -- more than six miles -- of empty lane between each bus. At a 15 foot car length and one car length between each car, you could fit more than a thousand cars in that lane instead of that one bus.
Even if every car has only one occupant and not one of the bus passengers are people who would have taken the bus if not for the bus lane, buses don't carry more than a thousand people, so you've reduced the carrying capacity of the road.
Using two minute intervals would still be consuming space that could fit hundreds of cars, so to be worthwhile you would have to have very large buses, they would have to be entirely full on every trip, and every passenger would have to displace a whole car, which is implausible because some people would have taken the bus either way and some cars would have had more than one occupant.
Moreover, if you would fill a bus every two minutes then you have enough density to justify operating a subway, in which case you still don't have a bus lane.
It's more efficient, not less. Bus lanes don't get built for buses that only have 12 trips a day. They're typically for places that have 10 minute frequencies or better. At 10 minute frequencies, with standard 40 foot buses, the lane capacity is about equal. With 2 minute frequencies, a single bus lane has a capacity about four regular lanes.
Under peak loads, during rush hour, that lane is worth every second of inconvenience to drivers. If they would rather have an extra lane and 3,000 additional drivers on the road, they'll regret it.