A street works authority may include in street works done in relation to a street under the private street works code a variation of the relative widths of the carriageway and of the footway or footways of the street.

No greater charge shall be imposed on a person by reason of any such variation than could have been imposed in respect of a carriageway or footway of the width prescribed for a new street of the same class by a byelaw or enactment with respect to the width of new streets which applied to the street when it was laid out; and any sum in excess of that charge shall be borne by the authority.