The output of your design will be dependent on the quality of elements you incorporated in it. For that reason, if you want to design site that relate to transport business, you need to go for perfect transport icons made with user experience in focus. The old design trends will not give you this as they are made with monochrome colours coupled with sketchy diagram. That is the reason why you have to go for the current trends design.
The current design trends come mainly with realistic image which will bring out the look and feel you want in your work. The background is another thing that made them perfect and suitable for different designs. What you simply need to do is to change the part you do not want as it is made with smart object feature.
Some of the available transport icons you need are: Bus icons, data transport image, school bus icons, Travel airplane icon, Cars Pixar 2 icon and others. That means you must get the kind of icon you need to represent your transport service.
If you are trying to illustrate about school with good transportation, you can use school bus transport icons. The travel airplane will be good for your travel company. For your car hire business the cars Pixar 2 icon will do the work.