HKL employs approximately 340 tram drivers. In the busy city traffic, the job of a driver demands precision and responsibility. As well as driving the tram, drivers sell tickets, give advice and carry out other customer service functions.

The traffic control centre in Töölö is the nerve centre for tram transport, and is in contact with all the trams in service. In the event of disruption, the control centre provides information about diversions and other instructions to drivers. Traffic control in Töölö and Hakaniemi also make sure that every tram has a driver all day long.

To make sure that the trams can cope with decades of hard use, the depots have to take good care of them. HKL Tram Traffic also employs approximately 200 maintenance and repair staff who perform a variety of tasks.

HKL Tram Traffic also produces many services concerned with building and maintaining the tram tracks from making track elements to maintaining tram stops.