JUSTICE GOLDENHERSH delivered the opinion of the court:

Defendants, Kirk Brown, Secretary of Transportation, Dale I. Klohr, district engineer--District 8, and Joseph E. Crowe, Jr., program development engineer--District 8, of the Illinois Department of Transportation, appeal from an order of the Circuit Court of St. Clair County granting summary judgment in favor of plaintiff, Drury Displays, Inc., in an action for a writ of mandamus to compel defendants to reissue permits to plaintiff for a billboard that had already been constructed. The issue on appeal is whether the trial court erred in granting summary judgment for plaintiff and in denying summary judgment for defendants. We affirm.

BACKGROUND

On July 24, 1996, plaintiff purchased property in East St. Louis, Illinois, with the intention of constructing an outdoor advertising sign. On July 25, 1996, plaintiff applied to the Illinois Department of Transportation (hereinafter the Department) for an outdoor-advertising permit for the property purchased the previous day. On August 12, 1996, permit No. 8/4277 was approved by Dale K. Klohr. The permit would expire within 180 days if a sign was not erected. Upon receipt of the permit, plaintiff applied and submitted the appropriate fee to the City of East St. Louis for a demolition permit to remove an existing structure located on the property. The demolition permit was issued on November 14, 1996, by the City of East St. Louis. On December 17, 1996, plaintiff again applied to the City of East St. Louis, this time for a permit to construct the proposed billboard. A fee was also required for this permit. The permit was issued on January 29, 1997, by the City of East St. Louis.

On February 4, 1997, plaintiff reapplied to the Department for another permit because its first permit, No. 8/4277, was near expiration. On February 5, 1997, Klohr again approved a permit for plaintiff. The new permit was No. 8/4304. Plaintiff then proceeded with the demolition of the existing structure on the property. The demolition was completed in March of 1997. Plaintiff also ordered steel for the construction of the billboard. The billboard was completed in May 1997.

Thereafter, on June 9, 1997, Norman Sampson, a Department employee, notified plaintiff by telephone that the Department erred in issuing the permits to plaintiff and that the billboard constructed on the property might have to be removed. On June 26, 1997, Klohr and Joseph E. Crowe, Jr., issued a notice of intent to revoke the permit to plaintiff, explaining that the permit violated section 522.200(d) of the Department's regulations (92 Ill. Adm. Code