Showing storm damage to 8-foot pavement south of Kane Springs, Imperial County.

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LOCATION OF ROUTES

The location of the California State Highway is largely specified by law. As built it has followed these instructions in Southern California, to-wit: A main line down the coast to San Diego and another trunk line down the San Joaquin Valley to Los Angeles. Connections of the county seats by the most practical routes is also specified. This latter has been partly accomplished by the acceptance of county highways as a portion of the State highway system.

A consideration of the routes in Southern California that have been adopted would be incomplete without referring to the Imperial Valley system. A main road was projected from San Diego to El Centro under the first bond issue.

In the First Biennial Report of the California Highway Commission, page 25, it is stated as follows: "The Second State Highways Act of 1915 sets aside the sum of three million dollars for the construction of the following projects, all to be by the most direct and practical route," one of which is "an extension of the San Bernardino County State Highway lateral to the Arizona state line near the town of Yuma, Arizona, via the cities of Brawley and El Centro in Imperial County."

This three million dollar fund was for roads to be built jointly by the State and Counties. Imperial County developed some water along this route by sinking wells and built a bridge across the San Felipe Wash near the southwest corner of the Salton Sea. The portions of this route remaining to be constructed are those lying within the irrigated district of Imperial Valley, namely from the Trifolium Waste, northwest of Brawley, to the High Line Canal, southeast of Holtville; also all of that portion lying between Yuma and the High Line Canal excepting 6.55 miles over the sand hills and one mile of Willite, ten miles east of Holtville; also all of that portion from the Trifolium Waste northwest of Brawley, to the north line of Imperial County. However, beginning at the Trifolium Waste and running north a distance of 18 miles on the west side of the Salton Sea, the State has completed 12 miles of 8' concrete pavement and some 6 miles of 15' pavement. A contract is now under way at the north line of Imperial County upon which approximately one mile of pavement has been completed to date. From the north line of Imperial County to Redlands there is, at the present time, one contract under way adjacent to the county line upon which approximately one mile of pavement has been completed. Three miles of pavement have been completed just south of Coachella and a grading contract between Redlands and Banning has just been finished. Between Beaumont and Banning approximately three miles of 16' concrete pavement was built by Riverside County. This will be taken over by the State as a part of the State Highway System.

About 55 miles of State highway has been completed on the route from San Diego to El Centro. The remaining 60 miles have either been graded or are under contract for grading by the State.

The general route as outlined by the law projects a road through the sand hills by way of Holtville and Knob Station to Yuma. A road has been constructed 8' wide of 4-inch plank over the "Sand Hills." This is practically impassable due to drifting sand for a greater portion of the year. Warning signs have been placed at both ends of it informing the public that a trip over it is hazardous. Our inspectors went over this road and not only experienced great delay in so doing but met marooned cars.

This Sand Hill road is not a feasible one to maintain. A general routing of through travel to Arizona points from the coast through these Sand Hills is ill advised.

The line from El Centro to Coachella on the west side of the Salton Sea passes through an unoccupied country where long hauls from the railroad are necessary for construction materials and where the water supply is scarce. The paving work completed has cost about $19,000.00 per mile, 12 miles of which is 8' wide. If the line had followed the Southern Pacific Railroad much of these construction difficulties and costs would have been reduced. Water, however, on the northeasterly side of the Salton Sea is very scarce. Drainage problems are much similar.

The Imperial Canal System extends to Niland and the country in this region is undergoing development. From Niland a road to El Centro would run through a highly improved region. The road to Arizona should be located generally along the Southern Pacific main line to Yuma both on account of the freight facilities that are offered for construction materials and the more direct communication with Arizona points from the centers of population of Southern California but more particularly because of the avoidance thereby of the drifting sand dunes, through which no road can be properly maintained. The people of the larger towns of Imperial Valley could reach Los Angeles points as readily by a line lying on the easterly side of the sea as one on the west, the distance being about the same. The Imperial Valley has its commercial connection either with San Diego or Los Angeles rather than to the east. The Arizona road system, which is being built to Yuma, would be best accommodated by a route along the Southern Pacific Railroad.

The attempt to maintain a road through the Sand Hills probably must ultimately be abandoned and the route suggested above constructed if permanent connections are to be established between California and Arizona points.

A careful study of the law and estimates should be made to determine whether the portions of this route which have been constructed on the west side of the Salton Sea and through the Sand Hills had better be abandoned and the route built along the Southern Pacific lines as suggested above, connections being made from Niland to Brawley and El Centro.

WASHINGTON NOTES RELATIVE TO PAVEMENTS

All new primary roads in the State of Washington are 20 feet wide, and the secondary roads are 16 feet. The 16-foot roads that have been built recently are 6 inches thick on the sides and 71⁄2 inches in the center. The original road from Olympia to Camp Lewis, built in 1914, was 16 feet wide, made of a 1-2-4 mix, 5 inches thick on the sides and 7 inches in the center. It was found insufficient to accommodate the traffic and in 1918 a second parallel slab 16 feet wide, 5%1⁄2 inches thick at the side and 7 inches in the center was laid.

Between Seattle and Everett there is an existing paved road 16 feet wide. A new road paralleling the original road within a few hundred feet is now being built with better alignment and grade. It is proposed to put a concrete pavement on this new grade 28 feet wide, 8 inches thick on the side and 10 inches thick in the center.

There is a law in the State of Washington that provides for co-operation between the State, the Counties and adjacent land owners for the construction of secondary roads. These local property owners pay 25% of its cost. Originally these roads were built 16 feet wide. The property owners now are insisting on an 18-foot minimum width. There are said to be no requests coming in to the authorities for narrower pavements; the insistence is that the roads should be of permanent construction. These three examples relative to width of pavements in Washington illustrate the growing demand on the part of the public elsewhere for wider and better roads. It is believed the same sentiment exists in California.

Mr. R. H. Thomson, former city engineer of Seattle and at present a prominent consulting engineer on road work in the Northwest, states that it is necessary to look into the future and prepare for still heavier traffic than we have been having in the past. He takes the position that the development of this freight traffic is of great importance. He believes that we should contemplate loads of 40 tons on six wheels and he proposes a slab 20 feet wide, 7 inches thick on the sides and 8 inches thick in the center. He states that for congested traffic, especially of large trucks with trailers traveling at night, a width of at least 20 feet is necessary.

The aggregates for concrete in Western Washington usually are obtained within a short distance of the work, pits often being opened alongside the road. The cost of these pavements in 1920 ranges from $2.07 to $2.90 per square yard, including the preparation of the sub-base.