1938 TRAFFIC FLOW

Here is the story of motor vehicle travel over the Arizona highway system during the year 1938. Foreign travel was up over 10 per cent as compared to 1937, indicating the ever-increasing attraction of the Land of the Sun and showing that good roads pay.

Good roads pay for themselves. This comprehensive study of traffic flow last year over the Arizona highway system shows conclusively that dollars spent in road building are dollars wisely spent.

The highways of Arizona, the finest on earth, each year are carrying more and more people more and more miles through this Empire of the Sun and Scenic Grandeur.

Years to come we will greet more and more visitors to our state. Our superior highway system will stand the state in good stead. Arizona's march of progress will be measured in terms of good roads.

THE Arizona Highway Department maintains approximately 3,701 miles of roads of various daily traffic densities ranging from 7000 vehicle density to as low as 50 per 24-hour period. Consequently, to properly appropriate moneys for maintenance, betterment and reconstruction of these roads, it is essential for the Highway Department to have at all times accurate data as to the amount of traffic flowing over the various sections of the highway system.

The second Wednesday of each month, under the supervision of the various maintenance foremen,, manual counts of traffic are recorded at 73 strategic points located over the entire highway system. In addition to this the Highway Department has in constant operation electric recorders counting traffic every hour of the day and every day of the year. These electric counters are located at strategic points on different routes and at different altitudes. From these electric counters ratios are developed each month to convert the manual 12-hour counts to an average 24-hour density. At the end of each year all of these counts are worked into final figures representing the average 24-hour traffic for the entire year over the various routes and sections of the Highway system. Very often it is hard to glance at figures and grasp their relative significance, whereas, if properly depicted, the importance of each is at once apparent. For this reason a flow map is made each year showing the average 24-hour traffic over the State Highway System. It would be impossible, and it is not intended, for a flow map to represent all details relative to traffic. For instance, the local traffic near several of the cities could not be shown on this map due to the large portion of the map it would cover. The flow map accompanying this article represents the average daily traffic for the year 1938 that traveled over the various routes of the Arizona Highway System and shows both foreign and local traffic. The main purpose of this map is for visual comparison between the various routes or portions of routes. Since 1932 the Arizona Highway Department has compiled these maps and has found them to be of great value in planning the network of roads that compose the State Highway System. These maps carry an array of visual statistics that would not otherwise be so apparent in unadorned figures, for one needs only to look at the flow maps of different years to note yearly changes in traffic flow over any route or portions of routes since 1932. Since only the 1938 map will accomAccompany this article, a short resume of the 1938 traffic relative to other years is given in paragraphs to follow.

Traffic as a whole for 1938 showed a gain of 5.88% over 1937 on the State Highway System. Local traffic (vehicles bearing Arizona license plates) showed only a slight increase, whereas foreign traffic (vehicles from other states) showed an increase of 10.58%. It was noted when computing the vehicle miles traveled over the different routes that local traffic increases were principally in the irrigated sections, or over routes connecting the irrigated sections of the state. Local traffic on nearly all remaining highways during 1938 was approximately the same as for 1937, some showing even a small decrease.

Probably the most interesting feature of traffic to the Arizona Public is in formation relative to foreign traffic, i. e., traffic composed of vehicles registered in other states.

Figures taken from a traffic survey made by the Bureau of Public Roads in the Eleven Western States for the year 1930 show that foreign traffic for that year amounted to 126,509,000 vehicle miles, the actual miles traveled by all foreign owned vehicles on the State Highway System in Arizona during the year 1930. The vehicle miles mentioned converted into the term of average daily density would mean that there was an average of 132 foreign vehicles per 24 hours equally distributed over the entire 2,633 miles of road that composed the State Highway System in 1930.

In 1938 foreign vehicles traveled 254,499,900 vehicle miles over the State Highway System, an average daily density of 188 foreign vehicles per 24 hours over the 3,701 miles of road that now compose the State Highway System.

The 1938 foreign increase in density over the year 1930 is 42.4%, whereas the 1938 foreign vehicle mile increase of 1938 over 1930 is 101.2%, a paradox of percentages, yet the following analysis will clarify this and also throw a new light on foreign traffic in this state.

The 1936 traffic survey conducted by the Arizona Highway Planning Survey showed that on roads other than the State Highway System only 6% of the total traffic was foreign, whereas, on the State Highway System 29% of the total traffic was foreign. Consequently it cannot be said that the great increase in the foreign vehicle miles traveled in Arizona in 1938 over the year 1930 was due wholly to miles added to the State Highway System.

The real reason for the seeming discrepancy between the 42.4% foreign density increase and the 101.2% increase in foreign vehicle miles traveled in Arizona as of 1938 over 1930 is the additional improved miles on the State Highway System to places that interest foreign traffic.

Summing up the foregoing in simple terms, it can be said that foreign vehicles entering the state in 1938 traveled 73, 823,440 miles more within the state than they would have traveled were highway conditions similar to the conditions of 1930.

It has been conservatively estimated that the occupants of foreign vehicles traveling in Arizona spend for sustenance, gas, oil, etc., the equivalent of 10% cents for each mile a foreign vehicle travels.

In 1938 foreign vehicles traveled 254,499,900 miles on the Arizona State Highway System, the occupants spending an approximate sum of $26,722,000 within the state. Had the road conditions been similar to the road conditions of 1930, foreign vehicles would have traveled only 180,676,460 miles, which would have meant a loss of $7,751,000 to the residents of this state, a sum exceeding the amount spent in 1938 by the Arizona Highway Department for maintenance and construction.

Diversion of all revenues that would otherwise be used for maintenance and improving the State Highway System, would directly hamper any increase of foreign traffic, for the more miles of improved roads to places of interest in this state to residents of other states the more vehicle miles will be traveled by foreign owned vehicles.

A considerable diversion of foreign traffic from some routes to others was noted when compiling the traffic data for 1938 and comparing them with figures for 1937. Notable among routes showing an increase in foreign traffic are listed below: U. S. Route 66, between Kingman and the Arizona-New Mexico line, with an increase of 168 foreign vehicles a day; U. S. Route No. 93, Kingman to Boulder Dam, with an increase of 92 foreign vehicles a day; State Route No. 64, Williams to Grand Canyon and Cameron, with an increase of 82 foreign vehicles a day; and U. S. Route 89, between Wickenburg and Fredonia, with an increase of 36 foreign vehicles a day. Other main routes showing a marked decrease in foreign vehicles are: U. S. Route No. 60, between Wickenburg and Blythe, 45 foreign vehicles a day decrease; U. S. Route No. 70, between Globe and Duncan, 77 foreign vehicles a day decrease; and on Route 91, in the northwest corner of Arizona, the decrease was 92 foreign vehicles a day.

Recently U. S. Route No. 66, which crosses the northern part of Arizona, was straightened and improved through New Mexico. This improvement, and the good roads in Arizona branching from U. S. Route No. 66 leading to the Grand Canyon, Boulder Dam, and other points of interest to residents of other states, are probably the main causes for the diversion of foreign traffic to this route.

Foreign traffic on routes other than those previously mentioned remained at approximately the same density as they were in 1937.

Looking at the flow map, the reader will note the routes preferred by foreign traffic. Some of this preference is probably due to the better road conditions of some routes over others, but mainly it is thought that the routes favored by foreign traffic are routes that lead to points in Arizona which interest residents of other states and, in some cases, are preferred routes because of favorable mileage to destination in other states.

Without a doubt, the foreign vehicle miles in this state can be greatly increased by improving or constructing roads leading to points within the state that are known to be of interest to residents of other states.