No-one will take your tickets as you enter a tram, bus or metro. This does not mean that you will get away with not buying a ticket. Sooner or later the under cover inspectors will ask to see your ticket. Please lock up you car and don't forget to put on your alarm, car theft is common and especially for foreign cars. If you are staying in an apartment for a period of time a short term Parking permit can be obtained at the nearest police station.
Permits are also available for the disabled here.
Traffic regulations in the Czech Republic are almost identical to those in most European countries. Drivers are not allowed to drink alcohol before and when driving. Safety belts must be used at all times. Motorcycle drivers and their passengers must use crash helmets. All accidents which result in death or injury or obvious damage to the vehicle must be reported to the police.