For a nation that consists of numerous islands, Denmark's road network is actually very efficient. The roads remain uncongested for the most part and there are plenty of car ferries that bring you from island to island. There are even a few underground tunnels that connect major islands and cities. The only roads that require a toll are the bridges that connect islands together. Traffic travels on the right side and the minimum driving age is 18 years old. Headlights must be on at all times and there are heavy fines for having a burnt out bulb. Renting a car in Denmark affords you the ability to explore this wonderful country at your own leisure. Denmark is also ahead of the game as it offers multiple bicycle lanes on most major roads in cities and scenic bike routes along the beautiful countryside.
Traveling by Rail:
The rail system is a very reliable means of transportation as it connects most of Denmark together. At times you will need to get on a ferry as the rail system doesn't connect some of the islands. Intercity train travel is very reliable and fast and prices remain affordable. Denmark even offers multiple international rail options, connecting Denmark with other surrounding European countries.
Traveling by Bus:
Traveling by bus is normally the secondary travel option to the rail system, but for local travel coach and bus travel is a great option. One thing that Denmark does brilliantly is combing the best of both rail and bus travel. Most passes are valid for both systems, which gives you more flexibility in the options you have while visiting Denmark.
Traveling by Boat:
Due to the numerous islands making up Denmark, boat and ferry travel is a crucial part to the infrastructure in Denmark. Services between the major cities is often cheaper and quicker, as they are designed to handle most traffic, but getting from island to island is very easy and efficient.
Traveling by Taxi:
Taxi service is available throughout Denmark, but more readily available in the major cities. Make sure the taxi has a meter and that it is a legit cab company. Tipping isn't necessary for cab drivers as a tip is already included in the metered price.