Why do repressive governments seek to control transportation and communication?

Repressive government is a form of government which control the people by their authority and power and do not allow people to speak freely in public or opposing against political parties or practicing severe violation of human right.

They tend to keep control on transportation and communication so that they do not meet people from other societies which are free or to talk freely and spread news to various people to standing for their rights.

what are the options?

answer; round wood logs, building materials like (plywood),also pulp and paper products;