The promoters shall, at their own expense, at all times maintain and keep in good condition and repair, with such materials and in such manner as the road authority shall direct and to their satisfaction, so much of any road whereon any tramway belonging to them is laid as lies between the rails of the tramway and (where two tramways are laid by the same promoters in any road at a distance of not more than four feet from each other) the portion of the road between the tramways, and in every case so much of the road as extends eighteen inches beyond the rails of and on each side of any such tramway. If the promoters abandon their undertaking, or any part of the same, and take up any tramway or any part of any tramway belonging to them, they shall with all convenient speed, and in all cases within six weeks at the most (unless the road authority otherwise consents in writing) fill in the ground and make good the surface, and, to the satisfaction of the road authority, restore the portion of the road upon which such tramway was laid to as good a condition as that in which it was before such tramway was laid thereon, and clear away all surplus paving or metalling material or rubbish occasioned by such work; and they shall in the meantime cause the place where the road is opened or broken up to be fenced and watched, and to be properly lighted at night: Provided always, that if the promoters fail to comply with the provisions of this section, the road authority, if they think fit, may themselves at any time, after seven days notice to the promoters, open and break up the road, and do the works necessary for the repair and maintenance or restoration of the road, to the extent in this section above mentioned, and the expense incurred by the road authority in so doing shall be repaid to them by the promoters.