H—4o

Conditions of Roads and Bridges.—Roads in many instances have deteriorated during the past decade, but from specific inquiries which the Transport Department has made it is clear that, although the road surfaces of to-day are in general probably weaker than the same surfaces were before the 1939-45 war, there are relatively few cases where present heavy traffic has broken up the road. The condition of bridges is more serious. Many of these structures were constructed of timber and have deteriorated to such an extent as to make them unsafe for heavy traffic. In a number of instances these bridges form a vital link in the roading system of the Dominion, and a vigorous programme of bridge replacement and repair is of first importance. Limitation op Loads on Bridges In order to safeguard certain bridges from the possibility of failure under heavy loads, many roading authorities have found it necessary to place a restriction upon the loads, and often upon the speed of motor-vehicles using the structure. In a number of instances where it is of a semi-permanent nature, such restriction has been affected by means of a local by-law, but many local authorities have availed themselves of powers contained in the Heavy Motor-vehicle Regulations which enable limits to be applied very readily if it is found necessary to protect a certain bridge. These powers were granted in 1948, and some 310 bridges are at present subjected to emergency load restrictions applied under these regulations. The limits imposed usually include a speed restriction as well as weight restrictions, but the following tabulation indicates the limits placed (a) upon gross loads and (b) upon axle loading :

Table E —Weight Restrictions on Bridges (a) Gross Load Restrictions

(b) Axle Load Restrictions

12

Gross Weight Restriction. Number of Bridges. Gross Weight Restriction. Number of Bridges. Over 10 tons 15 tons 1 10 tons 42 5 tons .. 41 9 tons 7 to 4£ tons 13 8 tons 44 3 tons and under 19 7 to 1\ tons 14 tons 78 Total 310 6 tons 36

Restriction of Axle Weight. Number of Bridges. Restriction of Axle Weight. Number of Bridges. 7 tons .. .. 6 tons tons 5 tons .. 4| tons 4 tons 3-Jr to 3-| tons 1 24 10 32 4 3 tons 2 to 2J tons Less than 2 tons No axle load limit 72 11 8 15 124 9 Total 310