There is an observation that if you replace a bus line with an equivalent tram / light rail line, the rail line will attract more passengers. The reasons are not fully understood. Comfort probably plays a role. Another reason might be that rail lines are easier to understand. Buses are almost universally confusing, while tracks make it obvious where the rail line goes.
Trams also have a capacity advantage, because the vehicles can be larger. And operating them is cheaper in the long term, because the vehicles are much more durable.
Seattle’s SLU Tram has similar problems, but it is more of the route it takes not being very useful. The first hill tram gets a lot more riders since it’s route actually goes between populated areas.
As someone who lived in NYC all their life and took public transit to school - buses suck. You have to stand in whatever weather is present: pouring rain, freezing cold, sweltering heat. Maybe there's a shelter, maybe someone is sleeping in it, maybe it's already full because it can only shelter a few people. No matter how "big" the stop is its always the same fucking pathetically small shelter. The ride is substandard with poor HVAC and in the colder months when it rains its miserable and very uncomfortable - damp and cold. Then the drivers have to deal with morons on the road so you get jerks and sudden stops from braking. As soon as I could I bought a car and to this day avoid buses like the plague. Thankfully I only have to take the subway to get to Manhattan as I live 2 blocks from the A train.
Somebody should put out a "Dummies Guide to Durable Trams" for the MBTA. The T is so bad that even transit advocates would rather drive when they need to be somewhere on time.
There is an observation that if you replace a bus line with an equivalent tram / light rail line, the rail line will attract more passengers. The reasons are not fully understood. Comfort probably plays a role. Another reason might be that rail lines are easier to understand. Buses are almost universally confusing, while tracks make it obvious where the rail line goes.
Trams also have a capacity advantage, because the vehicles can be larger. And operating them is cheaper in the long term, because the vehicles are much more durable.