The least expensive route at $1.4 billion is “Wl-A,”

The least expensive route at $1.4 billion is “Wl-A,” a revised version of one of the Fauquiercorridor alternatives. The most expensive option is to build two bypasses, Wl-A and an eastern route. Combined cost: $2.9 billion.

The report found that “an eastern or western bypass would result in an increase in the total number of vehicles crossing the Potomac River.” By the year 2010 between 56,000 and 77,000 vehicles would cross the river each day over a western bypass corridor. But a western bypass would only divert 7,000 to 15,000 vehicles per day from the existing beltway in the year 2010.

The western version of the superhighway, critics have pointed out in the past, would thus generate a net surplus in traffic, adding as many as 70,000 vehicle trips a day to already-clogged Northern Virginia roads.

Figures are more promising for an eastern bypass, which would “result in the highest diversion of traffic from ,existing Potomac River bridges,” the report states.

Another point critics make about the western corridors: 15,000 vehicles per day would amount to a three percent reduction in beltway traffic. Since BMI projects a 1.5 percent annual increase in beltway traffic, the slight reduction in congestion would be offset two years after construction of the bypass.

Last year BMI published a similar traffic report on numerous potential corridors of eastern and western bypasses. A summary introduction to that study did not mention that statistics within the study showed western routes would increase traffic over the Potomac.

Salvatore Bellomo, a highway engineer and a principal in the firm that bears his name, conceded after publication of that study that the proposed western bypass’s effect on the beltway would not be significant. He also agreed that at current rates of growth any diversion of beltway traffic would be offset two years after completion of a bypass.

This year’s more comprehensive study retains mention of reduced beltway traffic, but acknowl