Exhibit 4-21. Weave B

Weave B is located on I-87 northbound between the on-ramp from State Routes 2 and 7 on the lower left of the figure below (known locally as entrance 6) and the exit to Alternate Route 7 (known as exit 7).

Weave B is a Type A weave. Why? Here, both weaving streams must change lanes once in order to reach their final destination. Traffic entering from State Routes 2 and 7 (entrance 6) must change lanes once in order to stay on the mainline I-87 northbound. Traffic on I-87 northbound desiring to travel to Alternate Route 7 eastbound must change lanes once to reach this off-ramp.

Studies by local traffic engineers indicate that virtually no traffic entering from State Routes 2 and 7 also exit to Alternate Route 7 eastbound. They also estimate that 60 percent of the I-87 northbound traffic desires to exit to Alternate Route 7 eastbound, with the remaining 40 percent continuing on I-87 north past exit 7.