Auckland, Wellington, Montreal, Belfast, San Francisco - wherever there are dedicated bus lanes, private taxi operators are clamouring for the right of access to these public transport corridors.
It's obvious why they plead and pester. It's much harder to accept their reasoning.
When it comes to cluttering up rush-hour roads, taxis are just private cars with an extra person in them, namely the paid driver. Far from helping alleviate congestion, taxis add to it by having to travel empty to pick up their fare, then drive away empty into the melee afterwards.
If we concede that taxis have some special right to share a bus lane, then why not the chauffeur-driven limousine as well? After all, that's what a taxi is. And if we stretch the bus-only rule for taxis, why not allow red cars on Mondays, blue cars on Tuesdays and any vehicles with a pair of fluffy dice hanging in the rear window on Wednesdays, Thursdays and Fridays?
When you're stuck in a crowded rush hour general-traffic lane, the adjacent bus lane can look both empty and frustratingly inviting.
But that's part of the carrot psychology behind the exclusive bus lane. It's trying to woo you out of your car and on to the bus.
The taxi operators see it somewhat differently. They dream of gaining access to these free-flowing bus lanes so they can entice you out of your car and into their car instead. But if that were to happen, and Auckland's 3500 or so cabs suddenly homed in on this sudden rush-hour honey pot, what advantage the dedicated bus lanes then?
They'd become cluttered with cabs touting and plying for business while commuters fumed, along with their buses, as they slowly backed up behind like the bad old non-bus-lane days.
Auckland Transport has bowed to pressure from the taxi companies and from Auckland Central MP, Nikki Kaye, and has conceded a trial of taxis in selected bus lanes. It is "a reasonably complex matter", said AT chief operating officer, Greg Edmonds, in a recent letter to Co-op Taxis, not least because the law currently bans taxis from bus lanes.
This comes despite a report last year to the AT board recommending keeping bus lanes car free, "due to the potential compromise in bus-lane operation that can occur with the presence of taxis in bus lanes". The report did admit the possibility of a trial "on a case-to-case" basis.
An AT spokeswoman is keen to emphasise that "this concept is still in the very early stages", and is yet to be discussed with the bus operators. A major concern must be that the public transport goal is to double passenger numbers over the next 10 years.
But if you let taxis into the bus lanes now on the grounds that there's a certain slack in current capacity, how do you boot them out in five years' time when any slack has gone? Imagine the yells and screams and running to Nikki Kaye then.
In the United Kingdom, the traditional black cabs you hail from the footpath are generally permitted to use bus lanes, but not the private hire taxis more akin to the Auckland set-up.
There are reports galore. One to Belfast City Council in 2008 seems to sum up the situation. It observed, "There was little evidence from other UK cities of any movement to allow private hire vehicles into bus lanes ... and there was little evidence that private hire vehicles play any role in delivering sustainable transport systems".
A September 2012 report to the same council noted that letting taxis into bus lanes "is highly likely [to] impact on the performance of bus lanes in terms of bus speeds and journey times".
The report said it couldn't accurately predict the impact, but suggested "minimal" on the defeatist grounds that "a sizeable portion of non-permitted taxis already illegally use the bus lanes".
Auckland Council's transport chairman, Mike Lee, calls the current plan "a really dumb idea" that "defeats the whole purpose of bus lanes ... It is taking away the one advantage public transport has, of speed".
Bus driver union boss Gary Froggatt doesn't think "the odd taxi in a bus lane is going to cause problems". The odd taxi won't. But what happens when all 3500 come out to play?