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The following information is from a document used as the basis for the original design of IH 35 through Central Texas in the 1950s.

Publications: Texas and the Interstate Highway System, 1957

What Will the System Look Like?

The interstate highways are being built to the highest standards that engineers can now devise, including all of the safety features that we know about. As insurance that the system will not be outgrown by the time it is completed, the highways are being designed to handle the expected types and volumes of traffic that will exist in 1975.

The entire 2,905 miles in Texas--and the 41,000 miles in the United States-will be built on the controlled access principle with very few grade crossings. This means you will be able to drive from border to border and coast to coast without interruption from traffic lights.

The roads will be two, four, six or eight lanes wide, depending upon the traffic they will carry in years to come. Most of the system will be multilane divided, and on the two-lane highways the right of way must be wide enough that more lanes can be added at a later date as traffic increases.

Only in those sparsely-populated areas where the very highest standards are not needed will the highways be two lane, and only in these low-traffic areas will there be crossings at grade. There will be no railroad crossings, no stop lights, bad curves or steep grades. There will be no driveways from homes or businesses leading to the expressway lanes to create traffic hazards.

Traffic lanes will be at least 12 feet wide and shoulders at least 10 feet wide. The median strip dividing the lanes will be 40 to 60 feet wide in flat rural areas, 20 feet wide in urban and mountainous areas.

The roads are being designed for speeds of 70 miles per hour on flat land, 60 miles on rolling terrain, and 50 in mountainous and urban areas.

Historical 1957 Document

Types of Design

Design will vary with the locations of the highways and the traffic loads they carry.

Rural

In low-traffic rural areas they may be conventional two-lane roads. Only about 7,000 miles in the entire nation will be in this category and they will be designed so that other lanes may be added.

With Frontage Roads

In higher traffic areas the highways will go to four, six or eight-lane divided design, some with frontage roads added. The width of medians dividing the traffic lanes and the width of shoulders will vary according to whether the road is crossing flat country or is in a mountainous or urban area.

Overhead

In some localities the express lanes will be depressed while in others they will take to the air in an overhead design.

Depressed

Historical 1957 Document

Major Road Crossing

Structures such as these will be built where other state highways and major local roads intersect and cross the interstate highways. By using the correct lane or ramp, motorists will be able to change routes, take any route they wish, without crossing any conflicting lane of traffic.

Historical 1957 Document

Minor Road Crossing

For a very low-traffic cross road where no interchange is needed a simple grade separation will be constructed to move cross traffic over or under the expressway lanes.

Historical 1957 Document

Typical Urban Section

Typical Rural Section

Historical 1957 Document

Savings

In addition to the other benefits you will enjoy, these controlled- access express highways will mean a direct saving to you in both time and money.

Expressways already in use are cutting travel time in half. Their design permits traffic to move at much higher speeds than is possible on conventional streets, and since there are no grade crossings or intersections, stop-and-go driving is eliminated.

All this helps to reduce the cost of operating your car as well as saving you time. From studies made on existing highways it has been estimated that the average motorist can save more than one cent per mile by traveling on these highways.

An analysis made by the trucking industry shows that the savings realized by highway truckers when traveling on expressway-type highways is at least five cents a vehicle mile. This will mean even greater savings to you when this reduction in trucking costs is passed on to you in the form of lower prices for the goods transported over the highways.

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