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61 CHAPTER 19 CASE STUDY 10: LONG-RANGE REGIONAL TRANSPORTATION PLAN Case Study 10 involves the implementation of 30 years of New park-and-ride lots, and transit and highway improvements in the Seattle region. The New stations. improvements include all improvements that actually occurred USER'S GUIDE between 1990 and 2000, plus the planned improvements con- tained in the 20-year transportation plan from 2000 to 2020. 19.2 RESULTS OF PSRC MODEL RUNS The base PSRC model was run on three scenarios: 19.1 APPLICATION 1990 demand loaded on 1990 network, Two PSRC highway networks (1990 and 2020) were com- 2020 demand loaded on 1990 network, and pared to obtain the transportation system improvements that 2020 demand loaded on 2020 network. occurred between 1990 and 2000, plus the improvements planned between 2000 and 2020. The 2020 highway network The resulting VMT and VHT are shown in Table 50. The has 11 percent more centerline-miles of road and 13 percent PSRC model predicted that the 2020 highway and transit net- more capacity than the 1990 network (see Table 48). work improvements would result in a 4-percent increase in The 2020 highway network has the following traffic-flow daily VMT and a 9-percent reduction in daily VHT for the improvements over the 1990 network: region. New freeway HOV lanes, Freeway mixed-flow lane additions, 19.3 NCHRP 25-21 METHODOLOGY RESULTS New freeway sections, Urban street lane additions, The NCHRP 25-21 methodology was used to compute the New urban streets, impacts of not building the 30-year improvement program. Rural road lane additions, and The impacts on the 2020 base case trip tables of retaining the New rural roads. 1990 network were predicted by time period (AM peak, PM peak, and off peak) and by mode (SOV, HOV, and transit). The 2020 transit network has 32 percent more transit vehi- The revised trip tables were then reassigned to the 1990 net- cles and 21 percent more route-miles than the 1990 network work to determine the impact on VMT, VHT, and emissions. (see Table 49). The results are summarized in Table 51. The 2020 transit network has the following transit service In contrast with the standard PSRC model, which predicts improvements over the 1990 network: that the 30-year improvement program would increase VMT, the NCHRP 25-21 methodology predicts that the 30-year pro- New transit lines, gram of transportation improvements would decrease VMT Frequency increases for existing service, by 0.7 percent. The NCHRP 25-21 methodology furthermore Extensions of existing transit lines, predicts that emissions would be reduced by 6 to 7 percent.

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62 TABLE 48 Case Study 10: Highway improvements 1990 to 2020 Network Centerline-Miles Lane-Miles No. of Links Capacity-Miles Mean Free-Flow Speed (mph) 1990 10,266 15,704 15,171 17,802,716 21.2 2020 11,388 17,390 17,711 20,194,252 19.9 Difference 1,122 1,686 2540 2391536 -1.3 % Difference 10.9% 10.7% 16.7% 13.4% -6.1% TABLE 49 Case Study 10: Transit service improvements 1990 to 2020 Network Transit Vehicles Lines Route-Miles 1990 972 448 8,065 2020 1,286 542 9,716 USER'S GUIDE Difference 314 94 1,651 % Difference 32.3% 21.0% 20.5% TABLE 50 Comparison of baseline VMT and VHT estimates by PSRC model Scenario Demand Network Period VMT VHT MPH #902 1990 1990 AM 3hr Peak 12,049,800 384,443 31.3 #903 PM 3hr Peak 15,085,000 498,400 30.3 #904 Off Peak 37,113,300 1,175,500 31.6 Total Day 64,248,100 2,058,343 31.2 #1002 2020 1990 AM 3hr Peak 18,459,100 696,708 26.5 #1003 PM 3hr Peak 26,472,000 1,088,500 24.3 #1004 Off Peak 56,319,200 2,081,600 27.1 Total Day 101,250,300 3,866,808 26.2 #2002 2020 2020 AM 3hr Peak 19,363,700 630,847 30.7 #2003 PM 3hr Peak 27,670,300 977,495 28.3 #2004 Off Peak 58,668,900 1,927,400 30.4 Total Day 105,702,900 3,535,742 29.9 Difference 4,452,600 -331,066 % Difference 4.4% -8.6% Source: base case 2020 EMME2 databank, module 6.11. Impact of Difference = (the results for the 2020 demand loaded on the 2020 network) (the results for the 2020 demand loaded on the 1990 network). TABLE 51 Case Study 10: Regional results Scenario Period VMT VHT Speed THC CO NOX (mi) (hrs) (mph) (gm) (gm) (gm) 2020 AM Peak 12,152,900 381,540 31.9 Demand PM Peak 15,261,700 518,222 29.5 On Off Peak 37,208,800 1,179,200 31.6 2020 Total 64,623,400 2,078,962 31.1 45,000,186 714,064,881 46,356,879 Network 2020 AM Peak 12,313,300 446,992 27.5 Demand PM Peak 15,432,600 642,538 24.0 On Off Peak 37,331,500 1,200,800 31.1 1990 Total 65,077,400 2,290,330 28.4 48,285,393 761,290,211 49,348,300 Network Difference -454,000 -211,368 2.7 -3,285,207 -47,225,330 -2,991,421 % Difference -0.70% -10.17% 8.59% -7.30% -6.61% -6.45%