Delays on the city’s busiest streetcar route are being blamed mostly on passengers, not cars.

According to a new city staff report, the time it takes for people to get off the King 504 streetcar ranges from four to 15 minutes.

The study said service is most often brought to standstill to allow riders to board, pay their fare and collect a transfer from the driver.

TTC spokesperson Brad Ross told the CBC the current streetcar design contributes to the problem.

It’s believed the new fleet of vehicles will help prevent such delays because they allow passengers to board through four entrances.

However, it will be another three years before the new streetcars are rolled out on the King line.

The 504 line carries about 60,000 riders a day, and the streetcars share the road with about 20,000 vehicles on the average weekday.

A preliminary report goes to the city’s Public Works Committee next week with a final report due in 2015.