(a) The articles of incorporation of a company organized to erect and maintain a bridge or operate a ferry may specify the geographical area of the company's exclusive operations. No part of the area specified may be farther than three miles from the nearest point of the bridge or route of the ferry.
(b) Another toll bridge or ferry for hire may not be established on the same body of water within the area specified in the articles.
(c) Subsection (b) does not prohibit a bridge or ferry at the crossing of a road on the body of water that the commissioners court of the county in which the crossing is located declares to be a public road regardless of when that declaration is made.