Taiwan's Supreme Court has finalized a four-year prison term for a former top highway official, closing an 18-year corruption case and signaling that long-running graft prosecutions can still stick.

• Lee Tai-ming, who ran Taiwan's national freeway bureau, was found guilty of steering a highway interchange project to benefit a construction firm.
• The scheme dates back to 2008, when a retaining wall design was switched and the work was re-bid in a limited tender that handed the contractor an unfair gain.
• A colleague from the bureau's expansion office and two businessmen also received prison terms, and their illegal profits will be seized.
• The case bounced through the courts for years — an acquittal at first, then a six-year sentence, then three reversals — before sentences were cut under a law meant to compensate for excessive delay.
• Prosecutors have been told to activate measures to stop Lee from fleeing the country.

Outlook: With the verdict final, attention turns to whether Lee reports to serve the sentence or attempts to leave Taiwan.