Travelling in your own country
You can travel to another city. This can be done by clicking on the city name, in the upper right of the screen (Picture 1). A menu will open where you can select the city you wish to travel to (Picture 2). In the screen that appears, you have to select a taxi (or you may use your own vehicle, if you have one). When using a taxi, you only pay a fixed price per kilometer and you don't use any gas. Only your own vehicles use gas.
What to do if you are out of gas
If you are out of gas, you cannot transport items from and to your warehouse. However, you can buy gas from shops as gas is used after you buy it. Example: if you are out of gas and you buy 10 liter from a shop, you will only get 9 liter in your warehouse. Because you use at least 1 liter of gas for every transport, it is pointless to buy only 1 liter of gas.
Travelling abroad
Travelling abroad is only possible by using a ship. These can be found in a harbour. To find a harbour, go to the street selector and pick a street that has an anchor symbol. There someone has built a harbour. When there is no harbour in your city, you can always travel to another city and look for a harbour there. Kronenburg is the only city that can never have a harbour.
By buying a ticket for a ship, you can transport yourself or goods to another country. The transport will happen automatically, so you don't have to wait for the ship to take off. The departure time, set by the shipper, is the time when the ship itself actually sails away to the next harbour. A ship can then no longer be used until another route is made.