Why do trams attract more car drivers in cities than buses?

(its worth noting that trams only work where there is a high demand for passengers, which means cities or between cities, and that as such, they have a capacity 3 – 5 times that of a bus service on the same route.  See: https://bathtrams.uk/relative-carrying-capacity-cars-buses-trams/ Buses are great for low demand city routes and for rural areas)

First: Trams can, (perhaps counter-intuitively) cut through traffic making making them instantly very attractive to car drivers due to “Green Wave Traffic Light Preemption” . This is fully explained here.

Second: The nature of tram economics ( high capex,  low opex) means trams are more frequent – every 6 minutes so its just turn up and go – and this of itself reduces journey time; also no annoying hanging around and getting there early to make sure you don’t miss it, or nagging worry you have missed it.

Third: Trams are experienced as solid, expensive, more comfortable, quieter, and less jerky than a bus, and prestigious, unlike buses which are perceived as “cheap and cheerful” and therefore of low status and  generally used by those without a car. .

Fourth: Because a tram is a rail vehicle, and constructed completely differently to a road vehicle, it has much more space inside meaning people are not crammed together in multiple bench seats, and this is very attractive.

Fifth: Again because of their different construction, trams can have large multiple doors and this means boarding and alighting can be much more rapid in even a 250 seat tram, than a 70 seat bus, thus making for quicker journey times.

Sixth:  The effect of all this, as is borne out by World-Wide experience* is that significant numbers  drivers will actually leave their cars at home and use trams, (high prestige,  faster, comfortable, reliable, frequent, less crowded) https://bathtrams.uk/the-evidence-that-car-drivers-will-switch-to-trams-but-not-buses-1/        Since trams are about 90 times more effective in terms of using road this space, this creates road space for trams AND buses, which doesn’t happen with buses alone, who are predominantly used by those who don’t have cars.

*(A US Transportation Research Board analysis {US Transportation Research Board TRB Report No. 1221) of 40 years of data of buses replacing rail, and latterly rail replacing buses (as in Houston), showed that light rail (trams) carried 40% more trips than a like for like bus service, and that the majority of this difference was car commuters switching to rail. Passenger behaviour is a stronger signal of travel preference than attitude surveys.)

(Note This means that those who still wish to or must drive find it less inconvenient, because many of the previous car drivers will now be in the tram.)

Seventh: Parents will not trust their children to buses to get them to school because they are infrequent and unreliable – diesel buses often breakdown, there are driver shortages due to the stress of bus driving, and buses are delayed by traffic.  This is a key driver of the parents school run which is a major part of Bath’s traffic congestion.   In tram towns people will happily permit their children to use trams even if a tram change is involved because they are reliable and frequent.

Eight: There is also a subtle psychological effect, in that being in a bus is akin to having a lift in a strangers’ car, and subconsciously passengers are paying attention to and worrying about “driving the car” as it negotiates the traffic, traffic lights etc.

In a tram the user is completely isolated, has no ability to drive the tram and doesn’t need to subconsciously worry about at it, as the tram is like a train in its own isolated environment.  Thus tram travel is far less anxiety making than a bus journey.