While most transport in Scotland is booming, buses in some parts of the country are verging on crisis.
Air and rail travel is at record levels, CalMac ferries are carrying the most passengers for five years and there has never been as much traffic on the roads.
However, it is that very increase in other vehicles that is also helping to throttle the bus industry in some areas.
A fall in the cost of motoring has encouraged more people to travel by car, and in doing so, they are slowing down buses in towns and cities so much that buses are becoming an unattractive option for getting about.
One of Britain’s biggest operators put it in the starkest terms I’ve heard when he addressed a Transport Times conference in Glasgow last week.
Giles Fearnley, the managing director of First Bus, described the slowdown in bus speeds in Glasgow city centre as “really quite frightening”.
He said they now averaged only a fast walking pace of 3.5mph. You might as well have a man with a red flag in front.
“It’s no wonder people don’t travel,” he said. “We have really got to turn this around.”
The fears were widely shared among those at the conference, with none other than Roy Brannen, the chief executive of the Scottish Government’s Transport Scotland agency, admitting: “What really concerns me is bus.”
Urban congestion is wiping out all the time savings being achieved by passengers paying electronically with smartcards or their mobiles rather than cash.
The passenger figures look bleak - 80 million fewer bus journeys were made in Scotland in 2015-16 compared to eight years earlier - a 16 per cent fall, and to a near record low.
This is significant because buses provide by far and away the largest share of public transport - 487 million annual journeys, or around five times as many ScotRail.
It is important too because in many areas bus is the only public transport option, including in parts of cities with big rail networks like Glasgow.
However, the situation is also ironic because buses have never been more comfortable or greener, with air conditioning, wi-fi and charging sockets now commonplace.
There are also higher rates of passenger satisfaction in Scotland than south of the Border, according to independent watchdog surveys.
It all points to buses being the victim rather than the villain when it comes to their current plight.
The picture does vary across the country, with Edinburgh and the south east experiencing growth, along with the Highlands and Islands.
Factors include less congestion and more bus priority measures, like Edinburgh’s Greenways. The decline has been greatest in the densely populated west, along with other parts of the Central Belt, Tayside and the north east.
For David Begg, the conference’s organiser and a former Edinburgh transport convener, freeing buses from congestion is the key - and that could mean radical measures like charging cars to enter busy areas.
He said there was a need “to embrace a level of car restraint which appears to have gone out of fashion and is deemed to be too politically difficult”.
Mr Begg called for a conference just to address the bus problem, but ministers shouldn’t wait for that to focus on such a thorny but vital issue.