Atlanta’s streetcars were one of the slowest forms of public transportation available, and, probably the most expensive to the taxpayer, per rider. (thank you LukyPunchy!)

The system has an average traveling speed of 5 mph. Considering the average human walking speed is 2.5 to 4 mph,

The cost of the first 2.7 miles exceeded estimates at $99 million, or $36.7 million a mile, in 2015. In 2023, estimated costs ballooned to between $88 million to $107.5 million a mile for the proposed expansion with total project costs ranging from $176 million to $230 million

Considering MARTA has had a 60% reduction in ridership in the last decade, it's fair to point out that buses are much less expensive, the streetcar was free, but ridership was significantly below capacity, and now that the line costs $1 a ride, ridership has sunk to an average of 400 riders a day in 2022, so the busses capacity of 50 to 60 passengers? Easily would handle all the riders there are in a couple of slow commutes, and bus use can be easily scaled up or down with changing passenger demand.

https://www.georgiapolicy.org/news/atlanta-streetcar-grand-plans-and-failed-ambitions/