ply with appropriate standards consisting of continuous-welded rail for normal operations and heat-treated rail for short radius curves and special circumstances. The electrical systems are designed for safe, efficient, and continuous operation of the entire system with primary power supplied by the local electrical power companies. Electrical traction power will be supplied to the cars by means of a contact rail installed parallel to the running track. Spacing and capacity of traction power substations have been dictated by the demand of the operating schedules during peak periods. They are designed for an operating headway of 90 seconds even though the planned minimum headway is 120 seconds. These are the elements that were analyzed in detail in determining the estimate of total capital cost of Metro.

ESTIMATED RIDERSHIP

To measure Metro's revenue potential, an extensive analysis of ridership was undertaken utilizing the latest available regional data and most up-to-date proven computer techniques. To estimate ridership, certain basic assumptions were necessary regarding population and employment growth and levels of income. The following data developed by the Metropolitan Washington Council of Governments were utilized in the study:

Population of this area will increase from 2.0 million in 1960 to 3.5 million in 1980, and to 4.2 million in 1990. Most of this growth will be in the suburbs. The District of Columbia, Arlington County, Alexandria and Falls Church will continue to grow, but at a more modest rate.

Employment in the metropolitan area will increase from 1.0 million in 1965 to 1.4 million in 1975 and to 1.9 million in 1990.

Employment in the system's downtown area will increase from 273,000 in 1965 to 343,000 in 1975 and to over 500,000 in 1990.

The median income of the Washington area worker, set at $4,050 in 1960, will increase by 40 per cent by 1990 to $5,657 in 1960 constant dollars. Also for study purposes, it was assumed that by 1975 a freeway system will be in place involving the complete inner loop network of the North, South, East and Center Legs, completion of I-66 and the Three Sisters Bridge across the Potomac, completion of the North Central Freeway, I-95 and a portion of the Northern Parkway in Maryland. By 1990, the assumed highway system will include the Outer Beltway, Monticello Freeway, extensions of the Indian Head Highway, Southeast Expressway and Central Avenue.

This basic information for 1990 was utilized in the traffic forecasting procedure to establish three categories of 1990 ridership estimates.

First: the volume of all 1990 trips that would be made to and from each of the 680 zones into which the metropolitan area is divided for the purpose of traffic analysis.

Second: the proportion of these trips that would be made by more than one mode of transportation (bus and rail, car and rail).

Third: the number of public transportation trips using the rapid rail transit system.

It was estimated that the percentage of persons using public transportation to downtown Washington in peak hours would be raised from an estimated 40 per cent in 1965 to 60 per cent of a larger population once the new system is introduced. This estimate is comparable to the percentages that prevail in other cities with rail transit systems. During the peak period, 86 per cent of all 1990 transit trips would use rail services for at least part of the trip, and 90 to 97 per cent of all trips originating in individual Maryland and Virginia suburbs would use the rail service. The analysis of total traffic demands in 1990 included data on passenger volumes for peak hours and for the average weekday as well as annual volumes. Total Metro ridership for the year 1990 is estimated at 292,610,000. Average weekday patronage amounts to 959,000 and the average for a peak two-hour morning period is 252,500. A clear majority of these patrons will use the combined bus-rail system. Total transit trips for the year 1990, including trips by bus only, is estimated at 348,830,000.

PROBABLE FARES

Three possible fare systems were analyzed: zone fare, flat fare, and mileage fare. To determine estimated revenue for Metro, a zone fare system was assumed. Concentric rings extending from the center of the 10-mile square were established for the purpose of assuming additional fare zones. The first ring has a radius of 8 miles from the center of the square. Additional rings are 3 miles apart. This fare structure was used in estimating passenger movements and in determining gross passenger revenues for 1990. The zone-fare system used in the study was assumed to apply to feeder buses as well as the rail system. Free transfer between bus and rail was also assumed. In all cases the base fare will be shared between the bus company and rail system when the rider uses both modes to complete a trip. Where zone boundaries are crossed, the incremental fare increase will be retained by the mode used to cross the zone. The base fare was assumed to be 30 cents with an incremental 10-cent fare per zone. Between the District of Columbia and Maryland the incremental fare was set at 20 cents.

The Potomac River was established as a 10-cent zone boundary except for retention of Rossyln and the Pentagon within the central 30-cent fare zone. This fare system is comparable to the existing bus fares.

FEEDER BUS SERVICE

Metro patrons will have the added convenience of extensive feeder bus service, closely coordinated with rapid rail, providing wide coverage of the entire metropolitan area. Feeder bus routes will radiate to Metro stations from all sectors of the transit zone including remote areas not presently served by buses. The bus service will be sufficiently frequent and convenient that approximately 70 per cent of Metro's riders will arrive or depart from stations by feeder bus. Most Metro patrons will be within a 10-minute feeder bus ride of a rapid transit station. Because of the impact of rapid rail on the region's bus operations, and because coordination of the two modes is so vital to efficient transportation, extensive redesign of the present all-bus system was undertaken by WMATA for study purposes. Emphasis of the redesign was on altering the primary function of the buses from trunk line operations to feeder and local service operations with much greater attention given to cross-town and cross-county routes. The redesigned bus system was developed with the cooperation and assistance of the four local bus companies and the Washington Metropolitan Area Transit Commission.

Operating costs of the redesigned bus operations were analyzed in depth on the basis of vehicle hours, vehicle miles, vehicle requirements, and revenue passengers, utilizing latest available data on wages and other factors. Bus revenue estimates were developed on the basis of a zone fare structure involving a 50/50 split of base fares. The analysis projected operating revenues for the bus companies at a level of about 6 per cent above operating expenses. Current levels are about 4 per cent.