Performance Measure Summary - Boise ID There are several inventory and performance measures listed in the pages of this Urban Area Report for the years from 1982 to 2014. There is no single performance measure that experts agree says it all. A few key points should be recognized by users of the Urban Mobility Scorecard data. Use the trends The multi-year performance measures are better indicators, in most cases, than any single year. Examining a few measures over many years reduces the chance that data variations or the estimating procedures may have caused a "spike" in any single year. (5 years is 5 times better than 1 year.) Use several measures Each performance measure illustrates a different element of congestion. (The view is more interesting from atop several measures.) Compare to similar regions Congestion analyses that compare areas with similar characteristics (for example, population, growth rate, road and public transportation system design) are usually more insightful than comparisons of different regions. (Los Angeles is not Peoria.) Compare ranking changes and performance measure values In some performance measures a small change in the value may cause a significant change in rank from one year to the next. This is the case when there are several regions with nearly the same value. (15 hours is only 1 hour more than 14 hours.) Consider the scope of improvement options Any improvement project in a corridor within most of the regions will only have a modest effect on the regional congestion level. (To have an effect on areawide congestion, there must be significant change in the system or service.) Performance Measures and Definition of Terms Travel Time Index A measure of congestion that focuses on each trip and each mile of travel. It is calculated as the ratio of travel time in the peak period to travel time in free-flow. A value of 1.30 indicates that a 20-minute free-flow trip takes 26 minutes in the peak. Planning Time Index A travel time reliability measure that represents the total travel time that should be planned for a trip. Computed with the 95th percentile travel time it represents the amount of time that should be planned for a commute trip to be late for only 1 day a month. If it is computed with the 80th percentile travel time it represents the amount of time that should be planned for a trip to be late for only 1 day a week. A PTI of 2.00 means that for a 20-minute trip in light traffic, 40 minutes should be planned. Peak Commuters Number of travelers who begin a trip during the morning or evening peak travel periods (6 to 10 a.m. and 3 to 7 p.m.). "Commuters" are private vehicle users unless specifically noted. per Commuter A yearly sum of all the per-trip delays for those persons who travel in the peak period (6 to 10 a.m. and 3 to 7 p.m.). This measure illustrates the effect of traffic slowdowns as well as the length of each trip. Total Delay The overall size of the congestion problem. Measured by the total travel time above that needed to complete a trip at free-flow speeds. The ranking of total delay usually follows the population ranking (larger regions usually have more delay). Free-Flow Speeds These values are derived from overnight speeds in the INRIX speed database. They are used as the national comparison thresholds. Other speed thresholds may be appropriate for urban project evaluations or sub-region studies. Excess Fuel Consumed Increased fuel consumption due to travel in congested conditions rather than freeflow conditions. Congestion Cost Value of travel delay for 2014 (estimated at $17.67 per hour of person travel and $94.04 per hour of truck time) and excess fuel consumption estimated using state average cost per gallon. Urban Area The developed area (population density more than 1,000 persons per square mile) within a metropolitan region. The urban area boundaries change frequently (every year for most growing areas), so increases include both new growth and development that was previously in areas designated as rural. Number of Rush Hours Time when the road system might have congestion.
Inventory Measures 2014 2013 2012 2011 2010 Population (1000s) 375 365 355 345 335 Rank 86 88 90 91 91 Commuters (1000s) 186 182 177 172 166 Freeway 1,691 1,674 1,520 1,617 1,592 Arterial Streets 4,281 4,173 4,170 4,225 4,159 Value of Time ($/hour) 17.67 17.39 17.14 16.79 16.30 Commercial Cost ($/hour) 94.04 89.60 89.56 86.81 88.12 Gasoline ($/gallon) 3.57 3.68 3.35 3.31 2.84 Diesel ($/gallon) 3.81 4.02 4.01 3.77 3.11 System Performance 2014 2013 2012 2011 2010 Congested Travel (% of peak VMT) 31 -- -- -- -- Congested System (% of lane-miles) 27 -- -- -- -- Congested Time (number of "Rush Hours") 3.50 -- -- -- -- Total Fuel (1000 gallons) 5,673 5,005 4,621 4,522 4,432 Rank 82 85 86 86 86 Fuel per Peak Auto Commuter (gallons) 18 16 14 14 14 Rank 62 71 80 79 78 Total Delay (1000s of person-hours) 11,963 10,553 9,744 9,535 9,345 Rank 82 85 85 85 85 Delay per Peak Auto Commuter (pers-hrs) 37 34 32 32 32 Rank 66 73 80 81 80 Travel Time Index 1.16 1.14 1.13 1.13 1.14 Rank 65 79 81 80 76 Commuter Stress Index 1.20 1.18 1.17 1.17 1.17 Rank 57 69 77 76 74 Freeway Planning Time Index (95th Pctile) 2.23 -- -- -- -- Rank 43 -- -- -- -- Total Cost ($ millions) 269 241 226 226 228 Rank 84 86 86 86 86 Cost per Peak Auto Commuter ($) 833 747 700 699 707 Rank 74 79 85 84 85
Inventory Measures 2009 2008 2007 2006 2005 Population (1000s) 325 315 305 290 280 Rank 92 94 94 94 94 Commuters (1000s) 161 155 150 141 136 Freeway 1,540 1,500 1,620 1,575 1,530 Arterial Streets 4,011 3,905 4,045 3,810 3,680 Value of Time ($/hour) 16.01 16.10 15.47 15.06 14.58 Commercial Cost ($/hour) 89.75 81.52 82.56 80.43 78.05 Gasoline ($/gallon) 2.22 3.40 3.22 2.60 2.30 Diesel ($/gallon) 2.61 4.21 3.67 3.00 2.74 System Performance 2009 2008 2007 2006 2005 Total Fuel (1000 gallons) 4,340 4,560 4,643 4,324 3,993 Rank 86 86 84 85 86 Fuel per Peak Auto Commuter (gallons) 13 14 14 13 12 Rank 80 79 78 81 82 Total Delay (1000s of person-hours) 9,153 9,617 9,790 9,118 8,420 Rank 85 85 84 84 84 Delay per Peak Auto Commuter (pers-hrs) 33 36 38 37 36 Rank 74 66 55 57 58 Travel Time Index 1.14 1.15 1.16 1.16 1.15 Rank 76 76 66 63 72 Commuter Stress Index 1.18 1.19 1.20 1.20 1.19 Rank 62 65 55 54 58 Total Cost ($ millions) 227 238 251 240 229 Rank 86 86 86 86 86 Cost per Peak Auto Commuter ($) 703 736 779 745 711 Rank 85 82 80 84 85
Inventory Measures 2004 2003 2002 2001 2000 Population (1000s) 270 260 250 240 230 Rank 94 94 94 94 95 Commuters (1000s) 130 124 118 111 105 Freeway 1,465 1,375 1,340 1,300 1,250 Arterial Streets 3,500 3,470 3,385 3,310 3,190 Value of Time ($/hour) 14.10 13.73 13.43 13.22 12.85 Commercial Cost ($/hour) 74.17 72.23 70.86 71.38 70.47 Gasoline ($/gallon) 2.04 1.61 1.43 1.65 1.62 Diesel ($/gallon) 2.17 1.62 1.44 1.65 1.55 System Performance 2004 2003 2002 2001 2000 Total Fuel (1000 gallons) 3,708 3,342 3,115 2,884 2,479 Rank 87 86 88 88 90 Fuel per Peak Auto Commuter (gallons) 11 10 10 9 8 Rank 85 86 84 86 87 Total Delay (1000s of person-hours) 7,820 7,048 6,568 6,082 5,228 Rank 84 84 84 85 86 Delay per Peak Auto Commuter (pers-hrs) 34 32 32 31 28 Rank 66 71 69 70 78 Travel Time Index 1.15 1.13 1.13 1.13 1.11 Rank 66 76 75 73 80 Commuter Stress Index 1.18 1.17 1.17 1.16 1.15 Rank 66 68 67 68 76 Total Cost ($ millions) 220 204 194 183 162 Rank 86 86 86 86 88 Cost per Peak Auto Commuter ($) 682 631 602 566 501 Rank 88 89 89 89 90
Inventory Measures 1999 1998 1997 1996 1995 Population (1000s) 220 215 210 200 195 Rank 95 97 97 97 97 Commuters (1000s) 99 95 92 86 83 Freeway 1,200 1,170 1,005 915 870 Arterial Streets 3,095 2,750 2,620 2,450 2,310 Value of Time ($/hour) 12.43 12.17 11.98 11.71 11.37 Commercial Cost ($/hour) 66.76 65.76 66.83 66.20 64.27 Gasoline ($/gallon) 1.28 1.15 1.36 1.33 1.20 Diesel ($/gallon) 1.28 1.22 1.42 1.36 1.22 System Performance 1999 1998 1997 1996 1995 Total Fuel (1000 gallons) 2,162 1,847 1,639 1,488 1,313 Rank 91 91 91 91 92 Fuel per Peak Auto Commuter (gallons) 7 6 5 5 4 Rank 88 90 90 90 90 Total Delay (1000s of person-hours) 4,559 3,895 3,456 3,138 2,768 Rank 90 92 92 91 92 Delay per Peak Auto Commuter (pers-hrs) 26 23 21 20 18 Rank 78 83 86 85 87 Travel Time Index 1.10 1.08 1.07 1.07 1.06 Rank 84 90 94 91 93 Commuter Stress Index 1.13 1.12 1.11 1.10 1.09 Rank 83 85 89 90 93 Total Cost ($ millions) 146 127 115 106 97 Rank 91 92 92 93 93 Cost per Peak Auto Commuter ($) 451 394 355 330 299 Rank 91 93 94 94 94
Inventory Measures 1994 1993 1992 1991 1990 Population (1000s) 190 180 175 170 170 Rank 97 97 97 97 97 Commuters (1000s) 79 74 71 68 67 Freeway 830 790 750 700 675 Arterial Streets 2,240 2,145 2,065 1,800 1,685 Value of Time ($/hour) 11.06 10.78 10.47 10.17 9.75 Commercial Cost ($/hour) 62.23 60.84 59.01 57.31 55.03 Gasoline ($/gallon) 1.15 1.13 1.21 1.12 1.15 Diesel ($/gallon) 1.18 1.16 1.21 1.12 1.07 System Performance 1994 1993 1992 1991 1990 Total Fuel (1000 gallons) 1,177 1,108 1,032 965 945 Rank 92 91 90 90 88 Fuel per Peak Auto Commuter (gallons) 4 3 3 3 3 Rank 90 90 90 89 87 Total Delay (1000s of person-hours) 2,481 2,336 2,176 2,035 1,993 Rank 92 92 91 90 90 Delay per Peak Auto Commuter (pers-hrs) 17 17 16 16 16 Rank 87 85 85 83 81 Travel Time Index 1.05 1.05 1.05 1.04 1.04 Rank 96 93 92 94 94 Commuter Stress Index 1.09 1.09 1.08 1.08 1.08 Rank 92 90 91 89 84 Total Cost ($ millions) 89 86 83 80 81 Rank 93 93 92 91 91 Cost per Peak Auto Commuter ($) 276 266 256 246 251 Rank 94 93 93 93 92
Inventory Measures 1989 1988 1987 1986 1985 Population (1000s) 165 165 160 160 155 Rank 97 97 97 97 97 Commuters (1000s) 64 64 61 61 58 Freeway 650 625 600 580 550 Arterial Streets 1,565 1,480 1,455 1,460 1,440 Value of Time ($/hour) 9.25 8.83 8.48 8.18 8.03 Commercial Cost ($/hour) 52.81 50.04 48.53 46.57 47.83 Gasoline ($/gallon) 1.10 1.02 1.02 0.99 1.30 Diesel ($/gallon) 1.15 1.06 1.06 1.04 1.36 System Performance 1989 1988 1987 1986 1985 Total Fuel (1000 gallons) 765 642 489 471 454 Rank 89 90 91 91 91 Fuel per Peak Auto Commuter (gallons) 2 2 2 1 1 Rank 89 86 86 91 90 Total Delay (1000s of person-hours) 1,612 1,353 1,031 994 957 Rank 90 90 95 94 93 Delay per Peak Auto Commuter (pers-hrs) 13 11 9 9 9 Rank 84 86 88 87 83 Travel Time Index 1.03 1.03 1.01 1.01 1.01 Rank 95 94 100 100 100 Commuter Stress Index 1.06 1.06 1.05 1.05 1.05 Rank 96 93 94 93 91 Total Cost ($ millions) 69 61 48 48 47 Rank 91 91 94 93 93 Cost per Peak Auto Commuter ($) 214 189 150 149 147 Rank 92 93 95 93 93
Inventory Measures 1984 1983 1982 Population (1000s) 155 150 150 Rank 97 97 97 Commuters (1000s) 58 56 55 Freeway 520 490 475 Arterial Streets 1,435 1,050 990 Value of Time ($/hour) 7.75 7.43 7.20 Commercial Cost ($/hour) 46.47 44.23 43.08 Gasoline ($/gallon) 1.31 1.34 1.41 Diesel ($/gallon) 1.37 1.41 1.47 System Performance 1984 1983 1982 Congested Travel (% of peak VMT) -- -- -- Congested System (% of lane-miles) -- -- -- Congested Time (number of "Rush Hours") -- -- -- Total Fuel (1000 gallons) 439 349 241 Rank 91 91 96 Fuel per Peak Auto Commuter (gallons) 1 1 1 Rank 87 86 86 Total Delay (1000s of person-hours) 927 736 509 Rank 92 94 95 Delay per Peak Auto Commuter (pers-hrs) 8 7 5 Rank 83 85 95 Travel Time Index 1.00 1.00 1.00 Rank 101 101 101 Commuter Stress Index 1.04 1.04 1.04 Rank 94 91 90 Freeway Planning Time Index (95th Pctile) -- -- -- Rank -- -- -- Total Cost ($ millions) 47 39 28 Rank 93 94 95 Cost per Peak Auto Commuter ($) 147 122 87 Rank 93 95 95