The advantages below mean they are  attractive to car drivers – they will switch

• faster than traffic – green wave traffic light pre-emption means they are not delayed by traffic even though they share the same road space ie no segregation – cannot be applied to buses
• they run every 6 minutes
• being much longer can carry 350 – 450 passengers so people are not pushed together and car drivers are more likely to use them
• being of heavy railway origin the cars can have multiple large doors meaning boarding and egress is only 10 – 20 secs
• short boarding times mean trams pause in the traffic so when they restart there is at least a 20 second traffic free space in front – buses have to fight to re-join the traffic
• off-tram ticketing means boarding times are short
• once built trams cannot simply be withdrawn as an economy measure – the loan must be repaid – this encourages people to invest in shops and business due to transport certainty
• in tram cities 35% of journeys are made by tram compared to 5% in Bath by bus, so tram  profits are proportionally larger and can be used to subsidise unprofitable local and rural bus routes – this in turn attracts more drivers
• trams are highly reliable having only 3 moving parts in the power unit, whereas a diesel engine has over 2,000 parts requiring constant maintenance and being less reliable
• the foregoing make trams very attractive to car drivers – in Croydon trams, 20% of users were ex car users – so this frees up road space for feeder buses, rural buses, taxis, tradesmen and those who still want to drive in