There were several stations in Colombo and for many years the principal mode of transport within the city was the train.

The movie's sixth major character isn't a person but the ubiquitous cellphone that is the friends' principal mode of communication.

Buses are the principal mode of public transport.

The principal mode of personal transport is the car.

Bangladesh Railway is one of the principal modes of transportation in the country.

The donkey carriage - Austen's principal mode of local transportation - is also on display.

Their principal mode of attack seemed to involve shooting cheeseburgers at their target.

Since those early days, water is the principal mode of transportation.

The low crawl was a sniper's principal mode of movement.