ECONOMIC ANALYSIS OF ALTERNATE ROUTE LOCATIONS

THE GREATEST SINGLE HIGHWAY PLANNING CRITERION FOR THE COMPARISON OF LATERNATE ROUTE LOCATIONS IS IN TERMS OF THE ROAD USER BENEFIT-COST ANALYSIS. MANY OTHER FACTORS WHICH ENTER INTO A ROUTE LOCATION ARE: (1) TRAFFIC SERVICE, (2) EFFECT UPON LOCAL PLANNING OBJECTIVES, (3) EFFECT UPON LOCAL TRAFFIC PATTERNS AND STREET NETWORKS, AND (4) ENGINEERING. THE DIFFICULTIES WITH ORIGIN-DESTINATION ANALYSES ARE THE COMPLETE ANALYSIS MAY NOT GIVE A COMPLETE ANSWER. IT WAS CONCLUDED IN CONNECTICUT THAT THERE IS NEED FOR AN AREA APPROACH TO THE TRAFFIC PROBLEM BASED ON LAND USE OR ON AN EQUIVALENT METHOD OF APPRAISAL. THE GRAVITY MODEL METHOD DEVELOPED BY ALLEN M. VOORHEES, IS PRESENTED AND DISCUSSED. THE ADVANTAGES OF THE GRAVITY MODEL METHOD ARE SPEED AND EASE OF ANALYSIS AND A MORE COMPLETE ANSWER. IT IS BASED ENTIRELY ON FORECASTED LAND USE, RATHER THAN TRAFFIC GROWTH ON THE EXISTING HIGHWAY NETWORK. AT THE SAGAMORE CONFERENCE ON HIGHWAYS AND URBAN DEVELOPMENT THE HIGHWAY OFFICIALS SUMMARIZED SOME OF THE FACTORS INFLUENCING URBAN HIGHWAY LOCATIONS: (1) IMPACTS ON THE COMMUNITY, (2) PRESENT AND FUTURE TRAFFIC, (3) COST OF DEVELOPMENT, (4) HIGHWAY USER BENEFITS, (5) EFFECTS OF EXPRESSWAY OPERATIONS ON LOCAL STREET SYSTEMS, (6) COMPATIBILITY WITH LOCAL PLANS, (7) AESTHETIC CONSIDERATIONS, AND (8) NATIONAL DEFENSE, MR. VAN RIPER STATES IN THE DISCUSSION THAT ASIGNMENT OF TRAFFIC BASED ON ORIGIN AND DESTINATION INFORMATION IS A GOOD SOUND APPROACH BUT FOR URBAN EXPRESSWAYS THE PROBLEM MIGHT ARISE THAT THE FEEDER ROADS OR STREETS AND THE ACCESS STREETS WILL NOT HAVE THE CAPACITY TO GET THE TRAFFIC TO AND FROM THE EXPRESSWAY. LAND USE IS DISCUSSED BY MR. CHERNIAK. MR. JOHNSON AND MR. CHERNIAK DISCUSS TRAFFIC ASSIGNMENT BY THE GRAVITY METHOD. IN THIS METHOD THE ASSUMPTION IS MADE THAT LAND USES ARE SPECIFIED, RESIDENCES WILL BE IN CERTAIN PLACES, AND THERE WILL BE CERTAIN ZONES THAT THE TOWN PLANNING COMMISSIONS HAVE DESIGNATED AS LOCATIONS FOR POTENTIAL INDUSTRIAL DEVELOPMENT. MR. MOSKOWITZ MENTIONS THAT FORECASTING THE TOTAL AMOUNT OF TRAFFIC A ROAD WILL DEVELOP IS STILL GUESSING. MR. ESER STATES THAT IN INDIANA DUE TO THE LARGE MILEAGE IN THE INTERSTATE SYSTEM, IT APPEARS LIKELY THAT FUTURE RIGHT ANGLE TRAFFIC TO THE INTERSTATE SYSTEM MIGHT DEVELOP A PROGRAM PRACTICALLY AS LARGE AS THE PRESENT INTERSTATE SYSTEM.