TAR SEALING

Te Awamutu Courier, Volume 54, Issue 3892, 21 April 1937, Page 2

TAR SEALING

OTOROHANGA COUNTY ROADS. ENGINEERING VIEWPOINT. (Our Resident Representative.) Regarding a suggestion that certain roads within the Otorohanga County should be tar sealed, the engineer (Mr G. A. Jackson) reported at yester day’s meeting of the Council as follows: "I am instructed to submit an estimate of tar sealing those main highways in the county upon which tar sealing is warranted. The accepted theory is that tar sealing is not warranted on the score ot economy until such time as the annual maintenance cost per mile exceeds £l5O, and the daily traffic is in the vicinity of 500 vehicles per day. “The average annual maintenance cost ]>er mile on the secondary main Est. cost ot Proposed realign Name length ment and of highway in miles tar seal

“Corrugations: The cause of corrugations on metalled roads is the impact of wheels on solid surfaces, and the greater the load and speed the more severe the impact. Since the heavy motor vehicles regulations were amended to allow heavy trucks to travel at the rate of 30 miles per hour, corrugations have been made more noticeable on roads within this county. “The position is accentuated on the River Road by the long straight enabling trucks to get up high speeds. The remedy for corrugations is to keep a live surface of fine stone at all

highways in this county is £lO, and therefore tar sealing is not warranted as an economy measure. The Main Highways Board has already intimated that no tar sealing ot secondary highways will be considered in this county until at least the tar sealing ot the Auckland-Wellington main highway is completed to tne town ot Otorohanga. “For the council’s information I submit an estimate of the cost of tar sealing the most extensively used portions of highways, with comparative costs of maintenance. “The Main Highways Board has adopted a very high standard of realignment and formation as a precedent to tar sealing, and eonsequenrly the preparation of the roads for sealing would cost more than the actual sealing. The following schedule is submitted as an indication of the cost of re-aligning and tar sealing rhe. respective secondary highways. The estimate is based on realigning and tar sealing eighteen feet wide. No al lowance has been made for possible bridge and culvert replacement rendered necessary by re alignment. Council’s por- Present cost Annual tion of cost to Council cost per on a£2 for £1 per ann ‘ mile to basis for maint. Council it per mile tai sealed

times, so as to prevent wheels coming in contact with the solid surface, but this means going over the road almost continuously with a suitable ma chine for replacing the live surface as the traffic throws it ofl.“ COMMITTEE SET UP. The question was discussed at length and it was finally decided to set up a committee, with the inclusion of the engineer, to procure all possible information from ether counties that have had experience of tar sealing operations—-and results.

T<> KawaWharepuliunga 16.5 57 000 Pirongia-Kawhia 5.5 18,000 Ouruwhero 1.5 4,800 Mangaorongo 6.5 21,000

19.000 9 so 6,000 9 75 1,600 F. 75 7,000 5 80