WIDTH OF BRIDGES

Waipa Post, Volume 49, Issue 3554, 6 December 1934, Page 5

WIDTH OF BRIDGES

MAIN HIGHWAYS BOARD DECISION.

Information to effect that the Main Highways Board had decided to standardise bridge widths is contained in a comjmunication to county councils.

Bridges and first-class highways measuring less than 60 feet are to be provided with a: width of 24 feet between the kerbs. In the case of bridges of more than 60 feet io length, the width between kerbs is to be 22 feet to 24 feet. On secondclass highways the width allowed is 20 feet in all cases. The width on bridges of less than 60 feet in length on third-class highways is set down as 10 feet or 12 feet, while on those over 60 feet in length the width is given as 8 feet, 10 feet or 12 feet. The standard width between kerb hand-rails is 8 inches, but in cases of bridges of 8 feet and 10 feet in width, the clearance is to be increased to 12 inches, except in cases where hand-rails are splayed. As an indication cff the class into which a highway falls, first-class highways may be taken as those where _ the traffic intensity is over 300 vehicles per d : iem, second class 100 to 300 per diem, and third class under 100 vehicles per diem. Due regard midst, however, be given to future developments for the reason that the reinforced concrete structures now favoured will have a very long life and before tlhe design of any bridge is undertaken approval should be obtained for the widths proposed.