The provisions of this article shall not prevent the transportation department and the owner from entering into a written agreement whereby the owner agrees and consents that the department may enter upon his property without filing the complaint and declaration of taking and depositing the estimated compensation as provided in this article. The department shall have the same rights under such agreement with the owner in carrying on work on such project as it would have by having filed a complaint and a declaration of taking and having deposited the estimated compensation as provided in this article.
