3 CURRENT TRANSPORTATION 3.1 HIGHWAYS 7,000 6,500 10,000 7,000 10,000 7,000 FIGURE 4 3.1.1 Highway System Average Weekday Traffic Volumes 93 The areas thoroughfares that carry most of the commuter traffic 84,000 81,000 88,500 87,000 through the Braintree split area are: 92,000 93,000 9,000 N 8,000 10,000 9,000 10,000 · I-93 (from Route 24) 10,000 · The Southeast Expressway · Route 3 South 92,000 90,000 97,000 97,000 The Massachusetts Highway Department has jurisdiction over these 102,000 103,000 major highways, their interchanges, and arterial road segments near 0 HOV Volumes HOV Volumes 0 3,500 4,000 the interchanges. 5,000 4,000 92,000 90,000 Freeway facilities are composed of connected segments consisting 101,000 101,000 107,000 107,000 of the freeway itself, ramps, and weaving segments. These segments NC are connected in various sequences and there are significant NC interactions between them that sometimes create a bottleneck that 34,000 8,000 NC reduces the capacity of the freeway to that of the bottleneck. 9,000 NC 10,000 93 16,000 82,000 92,000 97,000 NC Presently, the Southeast Expressway has four travel lanes in each NC 35,000 NC direction. During the AM peak period (6:0010:00 AM), the leftmost 36,000 28,000 21,000 29,000 64,000 38,000 30,000 21,000 30,000 NC 68,000 4,000 southbound lane is operated as an HOV lane for traffic moving 40,000 35,000 22,000 32,000 75,000 43,000 11,000 northbound. The situation is reversed during the PM peak period 46,000 13,000 50,000 13,000 (3:007:00 PM), when the leftmost northbound lane is operated as 3 49,000 55,000 an HOV lane for traffic moving southbound. Thus, during each peak 57,000 period, the peak direction has five travel lanes serving trafficfour 37 49,000 51,000 66,000 NC general purpose lanes and one HOV lane. NC NC 57,000 69,000 NC NC 75,000 15,000 NC 18,000 5,000 30,000 12,500 98,000 29,000 11,000 15,500 13,000 106,000 37,000 30,000 13,000 Route 3 South has three travel lanes in each direction from 30,000 33,000 16,000 14,000 114,000 6,000 39,000 35,000 13,000 15,000 7,000 40,000 interchange16 (Route 18) to the split. South of Route 18, there are 10,000 53,000 NC 53,000 NC two lanes in each direction, but during the peak period of travel, 46,000 58,000 24,000 20,000 99,000 54,000 23,000 traffic is allowed to use the shoulder/breakdown lane in the peak 107,000 57,000 23,000 115,000 direction as a travel lane. Use of the shoulder/breakdown lane as a 10,500 101,000 11,000 travel lane is restricted to the segment with two lanes. There is no 109,000 12,000 3 115,000 93 HOV lane on Route 3 South. 2,500 3,000 3,000 37 77,000 75,000 1992 33,333 82,000 81,000 The stretch of I-93 between the split and Route 24 has four travel 15,000 88,000 88,000 16,000 1999 33,333 lanes in each direction. This stretch has no HOV lane and traffic is 15,000 2003 33,333 not allowed to use the shoulder/breakdown lane as a travel lane. Not Counted NC 101,000 109,000 115,000 The following section describes the traffic volumes at the split and The HOV lane became the connecting highways. operational in 1995. 10 3.1.2 Traffic Volumes 400 93 400 300 FIGURE 5 Several kinds of data were collected for quantifying and evaluating 250 300 450 2003 AM Peak Period: Balanced Traffic Volumes 600 existing traffic conditions. As part of this study, MassHighway 400 3,300 6,500 4,750 5,800 conducted Automatic Traffic Recorder (ATR) counts in 2003 for 4,800 5,500 5,600 4,400 300 I-93, the Southeast Expressway, and Route 3 South. These counts 600 N 800 are summarized, along with those collected in 1992 and 1999, in 600 400 550 Figure 4 (see page 10). 600 400 Between 1992 and 2003, average weekday traffic on the I-93 3,700 6,800 5,300 6,400 segment between Routes 24 and 37 increased by 14 percent; on 5,400 6,300 6,200 Route 3 South by 15 percent; and on the Southeast Expressway by 4,800 1,200 HOV Volumes 1,400 18 percent. These increases represent a rate of about 1.2 to 1.3 1,000 percent per year. The AM and PM peak-period traffic volumes 600 presented in Figures 5 and 6 indicate that during the peak periods, 3,700 8,000 traffic volumes in the peak direction of travel remain essentially 5,300 7,800 5,400 7,300 4,800 6,800 constant or decrease slightly, due to traffic congestion and capacity 1,000 1,600 700 1,550 restrictions. Thus, the observed growth in traffic over the 11-year 900 1,400 800 period is manifested partly by the expansion of the number of hours 600 7,300 2,300 700 of congestion and partly by the growth of the off-peak period traffic 6,900 2,300 950 6,500 2,100 900 volumes. 93 6,200 2,100 700 1,750 3,600 2,000 3,300 3,100 1,300 2,700 5,900 3,500 At the uncongested sections of the freeways, the peak hour volumes 2,800 1,800 2,400 5,400 2,000 200 2,800 1,600 1,700 4,900 500 1,100 4,700 500 range from 1,900 to 2,200 vehicles per hour per lane. At the 250 1,500 700 bottlenecks, where queuing, weaving, merging, and diverging 2,300 1,200 2,400 1,300 activities take place, peak hour volumes are in the range of 1,100 to 2,200 800 2,200 1,600 vehicles per hour. 3,000 3,000 37 2,600 3,600 3.1.3 HOV Lane Traffic Volumes 4,100 3,700 2,400 850 3,200 3,300 1,600 650 50 5,800 1,500 3,600 1,700 250 1,200 2,600 3,400 1,000 150 The Southeast Expressway HOV lane opened in 1995 as one of the 400 400 7,100 950 900 500 600 6,700 1,600 2,600 150 700 850 200 500 600 800 5,800 1,800 1,800 500 mitigation projects for the Central Artery/Tunnel project. Since then, 300 1,200 1,700 500 800 600 2,400 1,700 700 entry has been limited to carpools, vanpools, and buses. The 3,600 600 1,800 1,150 500 3,700 3,800 1,700 1,050 operating policy for the HOV lane has changed over the years; first 6,100 3,800 3,000 1,200 1,050 7,400 3,700 2,000 7,500 3,600 2,000 400 6,600 the entry rule was three or more occupants per vehicle; after that 700 1,300 600 there was a sticker program (red and green) that allowed certain 500 3 93 numbers of vehicles with two-person occupancy to enter the HOV 5,800 7,200 lane on alternate days. This was later expanded to allow all vehicles 6,500 50 5,500 100 37 100 6-7 AM 55,555 with stickers to use the HOV lane on all days. Presently, any vehicle 100 2,650 6,600 3,800 6,600 with two or more occupants meets the entry requirements for the 650 7-8 AM 55,555 4,100 6,200 1,000 3,900 5,500 1,300 8-9 AM 55,555 HOV lane. 1,100 6,300 9-10 AM 55,555 7,800 The three-or-more occupancy rule, which was introduced in 1996, 8,100 resulted in maximum volumes of 375 and 400 vehicles per hour for 7,100 the AM and PM peak periods, respectively. With the introduction of 11 the two-person-occupancy sticker program in 1998, these volumes 1,150 400 1,200 450 increased to a maximum of 550 and 525 vehicles per hour for the AM 1,100 600 FIGURE 6 1,000 400 and PM peak periods, respectively. In February 1999, when the two- 2003 PM Peak Period: Balanced Traffic Volumes person-occupancy sticker program was expanded to all days, the 93 5,100 maximum volumes increased to 825 vehicles per hour during the AM 5,550 4,650 4,600 4,800 4,200 4,500 peak period, and 550 during the PM peak period. In June 1999, when 5,200 N 3 700 the HOV lane was opened to all vehicles with two or more occupants, 750 850 800 1,000 650 with no sticker required, the lane use increased to 1,300 vehicles per 1,100 hour during the AM peak period and 1,000 during the PM peak period. 900 Presently, the volumes in the HOV lane typically do not exceed 6,400 5,800 1,3001,400 vehicles per hour either northbound during the AM peak 5,600 5,400 5,300 5,600 period or southbound during the PM peak period.