The Commissioner of Transportation shall maintain any sidewalk, including the removal of snow and ice, abutting property acquired for highway purposes, from the date of acquisition until the section of highway for which the property was acquired is completed. The commissioner may agree with the municipality in which such sidewalk is located that it perform such maintenance of, and removal of snow and ice from, such sidewalk as the commissioner deems necessary and reimburse the municipality for the expense thereof; provided such agreement shall not, for the purposes of section 13a-144, release the commissioner from the duty to maintain such sidewalk. Any person using such sidewalk shall do so at such person’s own risk when such sidewalk is posted in accordance with section 13a-115.