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HomeMy WebLinkAbout02/24/1964 (2)By Commissioner Alter February, 1964 COMMENTS ON STANDARD SPECIFICATIONS FOR SUBDIVISIONS General Comments 1) Construction - No effort is made here to judge the technical and engineering standards inherent in this report. These are standards to be judged by engineering experts. However, the specification of 5 inches of cement treated base on all roads as opposed to six or eight inches of untreated base deserves additional study. Statements have been made by competent engineers, that cement treated base is too rigid and too brittle to stand up for any protracted period of time under normal road conditions, particularly when placed over adobe. These engineers maintain that eight inches of untreated rock base is far more durable than five inches of cement treated base because of its greater flexi- bility and strength. These engineers also claim that costs will be raised unnecessarily since only a limited few contractors have the special equipment required to lay treated base construction. The road widths as specified are unnecessarily wide. The pavement on primary roads where neither berms or gutters are required, is specified at 30 feet. Where berms are required, the pavement is specified 2736 feet. It is a greater width of pavement �w than any now existing in Los Altos Hills except for newly built E1 Monte Avenue. There is no necessity for a pavement to be any greater between berms than 24 feet on the busiest roads. West Fremont Avenue, our most heavily travelled road, has only a 24 -foot width of pavement on that newly constructed section near the Gardner Bullis School and it is ample width for the traffic carried. As long as we do not intend to have high speed or four lane roads in Los Altos Hills, there is no need for a pavement of more than 24 feet on any of our primary roads. As a matter of interest, here are some random samplings of road widths just made and fairly accurate for comparison. These are typical roads in this area. Magdalena newly paved section - 23 feet; Ravensbury - 23 feet, and Summerhill - 2236 feet -- are all county roads. Robleda - 19 feet; Purissima - 20 feet; Concepcion - 20 feet; Elena (newly built section) - 2636 feet, old section 18 feet; Altamont - 18 feet, and Moody - 18 feet -- all town primary roads that are not doing too badly. Widening these roads to 24 feet would be helpful but going to 30 feet would ruin their appearance and is unnecessary. There can be no purpose for a rolled curb standard inasmuch as curbs of any kind are not recommended in Town. A pavement of 24 feet is specified between berms on secondary roads or 2614 feet with berms which is only 336 feet less than a primary road. Again this is far in excess of our �W needs and desire to remain rural. This width should be no more than 20 feet and would do well to be 18 feet. Private roads with a 20 -foot pavement are ridiculously wide. A private road serves five homes. It is not necessary to provide a pavement to these homes any wider than 14 feet. No specifications have been set up for roads not requiring a berm, curb or gutter. What has happened to our concept of a truly rural community? How are we going to create new roads with the rural charm of Sunset - 14feet, O'Keefe - 17 feet, Hilltop - 1'7 feet, Quinnhill - 1? feet and many other similar rural lanes under standards where the minimum pavement width is 20 feet. The path requirements are also far beyond our needs. Paths do not need to be six feet wide with header boards. A four -foot path is more than sufficient for 99% of the locations in Town. The new sidewalks now being completed on E1 Monte Avenue are only 5 feet wide. Nor is it sound to require paths on private roads or cul-de-sacs. There is never enough traffic on either of these roads to make walking in the road a hazard. Requiring a six-foot path of asphalt and header boards on a private road verges on the ridiculous. Following these Road Standards would urbanize Los Altos Hiils faster than anything else we might do. -2- t Commissioner Alter 4t February, 1964 Comments on Standard Specifications for Subdivisions Two Pages LOS ALTOS HILLS - NEW SUBDIVISION STANDARDS Cement Treated Base Should never be used in an asphalt pavement structure that is founded on a yielding subgrade of any sort. Since the cement treated base is brittle and relatively weak, it cannot take the deflections that are normal over yielding subgrades. Adobe soils, in most cases, have relatively high deflection characteristics. 9