§ 18

The commonwealth shall be liable for injuries sustained by persons while traveling on state highways, if the same are caused by defects within the limits of the constructed traveled roadway, in the manner and subject to the limitations, conditions and restrictions specified in sections fifteen, eighteen and nineteen of chapter eighty-four, except that the commonwealth shall not be liable for injury sustained because of the want of a railing in or upon any state highway, or for injury sustained upon the sidewalk of a state highway or during the construction, reconstruction or repair of such highway. The amount which may be recovered for any such injury shall not exceed one fifth of one per cent of the valuation of the town in which the injury was received, nor shall it exceed four thousand dollars. Notice of the injury as required by law shall be given to a member of the department.