completed to the reasonable satisfaction of the street authority, unless otherwise agreed in writing,  be maintained by and at the expense of the undertaker for a period of 12 months from its  completion and at the expiry of that period by and at the expense of the street authority.  (3) The structure and highway surface of the new bridge must be maintained by and at the  expense of the local highway authority from the date of the completion of the new bridge.  (4) Where land not previously part of the public highway comes to form part of the public  highway by virtue of the construction, diversion or alteration of the streets set out in Schedule 4  (permanent stopping up of highways and private means of access and provision of new highways  and private means of access), unless otherwise agreed with the street authority, the land is deemed  to have been dedicated as public highway on the expiry of a period of 12 months from completion  of the works to the street that has been constructed, altered or diverted.  (5) In any action against the undertaker in respect of loss or damage resulting from any failure  by the undertaker to maintain a street under this article, it is a defence (without prejudice to any  other defence or the application of the law relating to contributory negligence) to prove that the  undertaker had taken such care as in all the circumstances was reasonably required to secure that  the part of the street to which the action relates was not dangerous to traffic.  (6) For the purposes of a defence under paragraph (5), the court must in particular have regard to  the following matters—  but for the purposes of such a defence it is not relevant to prove that the undertaker had arranged  for a competent person to carry out or supervise the maintenance of the part of the street to which  the action relates unless it is also proved that the undertaker had given the competent person  proper instructions with regard to the maintenance of the street and that the competent person had  carried out those instructions.  (7) The date of completion of any works to a highway pursuant to this article is to be agreed by  the undertaker and the local highway authority.  (8) The date of completion of any works to a street which is not and is not intended to be a  highway pursuant to this article is to be agreed by the undertaker and the street authority.  9.  On the date on which the roads described in Schedule 3 (classification of roads, etc) are  completed and open for traffic—  (a) the roads described in paragraphs 1 to 16 of Part 1 (A12 and A146) of Schedule 3 are to  be classified as the A12, as if such classification had been made under section 12(3)  (general provisions as to principal and classified roads) of the 1980 Act;  (b) the roads described in paragraphs 17 to 24 of Part 1 of Schedule 3 are to be classified as  the A146, as if such classification had been made under section 12(3) (general provisions  as to principal and classified roads) of the 1980 Act; and  (c) the roads described in Part 2 (other roads) of Schedule 3 are to be classified as set out in  that Part and are, where specified in that Part, to be classified roads for the purpose of any  enactment or instrument which refers to highways classed as classified roads, as if such  classification has been made under section 12(3) of the 1980 Act.  (e) where the undertaker could not reasonably have been expected to repair that part of the  street before the cause of action arose, what warning notices of its condition had been  displayed,  (d) whether the undertaker knew, or could reasonably have been expected to know, that the  condition of the part of the street to which the action relates was likely to cause danger to  users of the street; and  (c) the state of repair in which a reasonable person would have expected to find the street;  (b) the standard of maintenance appropriate for a street of that character and used by such  traffic;  (a) the character of the street and the traffic which was reasonably to be expected to use it;  Classification of roads, etc.  15