Mammoth elevated highways, which will alleviate traffic problems in cities, were visualized yesterday in a speech by Hawley S. Simpson, of New York, noted traffic research engineer, at the Harvard Bureau for Street Traffic Research. High cost would prevent them from becoming immediately practical, he said.

Speaking of ways in which "facility of communication" might be effected, Hawley said that conditions in city street traffic might be improved by "the construction of new surface streets, the widening of existing thoroughfares or the construction of elevated highways."

Tells of Expense Involved

While Hawley spoke of "the beginning of some elevated highway construction in cities before long," and mentioned the fact that it has been tried in small cities, he doubted if they could be economically justified. "Their cost will be in the neighborhood of $5,000,000 a mile in our larger cities, considering both construction costs and damages to abbutors, and then will be useful only to those having long distances to travel."

The cost would make construction of such highways impractical, and regular surface roads would be more convenient for short distances. The proposed highways would not "generate a sufficient volume of passenger traffic" to make the scheme pay interest by means of tolls.

Storage Space Necessary

Admitting the economical possibility of the construction, Hawley maintained that storage space for cars would be needed in adjacent buildings. "It is highly improbable that the automobile users will have financial ability to meet storage charge in off-street spaces in any type of building when we can visualize today," he said.

Concluding his address, Hawley thought there was no pressing need for rebuilding cities or constructing express highways for purely local traffic. "I believe that our streets are capable of handling considerably greater volumes of traffic than they are at present carrying," he said.