Since 2004 there is a tunnel with two underground tram stations (Spui and Grote Markt) in the city centre; it is shared by tram lines 2, 3 and 6. See nl:Haagse tramtunnel for pictures with text in Dutch.
HTM has five simple rules that apply to all our buses and trams: no smoking, no eating, no drinking, no vandalism and for your own safety no speaking to the driver while the vehicle is in motion.
You must be in possession of a valid ticket in all HTM vehicles and at the security stops.
For example, you get 12 months of travel but pay for only 10, you can pay in instalments (at no extra cost) and you will not be affected by any price rise during the year in which your ticket is valid.
Part of HTM is SVD, the city bus company of Dordrecht.
HTM has sold its shares in SVD, due to the ministery of transport and public works opposing the company competing for public transport concessions in tenders.