While the expenses for travelling in the home town can be predicted, for travelling from one city to another, over a long distance, the expenses involved cannot be predicted easily . Most people will plan their travel making some provisions, however their plans may get changed or upset due to factors beyond their control.

For example due to poor weather conditions or a technical problem, the flight or trip may get delayed or cancelled , and the person may have to change the travel plans at the last moment or spend more money to reach their destination. So it is advisable to keep enough cash while travelling for any unexpected problem.