1、 Michael P. Lewis, President Director, Rhode Island Department of Transportation Bud Wright, Executive Director 444 North Capitol Street NW, Suite 249, Washington, DC 20001 (202) 624-5800 Fax: (202) 624-5806 www.transportation.org ERRATA for Guide for the Development of Bicycle Facilities, 4th Editi
2、on (GBF-4) February 2013 Dear Customer: Recently, we were made aware of some technical revisions that need to be applied to the Guide for the Development of Bicycle Facilities, 4th Edition (GBF-4). Please replace the existing text with the corrected text to ensure that your edition is both accurate
3、and current. You may also download a copy of the errata at http:/downloads.transportation.org/GBF-4-Errata.pdf AASHTO staff sincerely apologizes for any inconvenience. Page Existing Text Corrected Text Chapter 3 3-4 Table 3-2 in Row 1, Typical Upright Adult Cyclists, Feature column reads: Feature Va
4、lue U.S. Customary Metric Deceleration rate (dry level pavement) 0.16 ft/s 24.8 m/s 2Deceleration rate for wet conditions (5080% reduction in efficiency 8.010.0 ft/s 22.43.0 m/s 2Revise to read: Feature Value U.S. Customary Metric Deceleration rate (dry level pavement) 810 ft/s 22.43 m/s 2Decelerati
5、on rate for wet conditions (5080% reduction in efficiency 25 ft/s 20.61.5 m/s 2Add new sixth row to read: Feature Value U.S. Customary Metric Coefficient of friction for braking, wet level pavement 0.16 0.16 Page Existing Text Corrected Text Chapter 5 5-7 Figure 5-3 top illustration, the drop dimens
6、ion reads: Drop is 6 ft 1(.8 m) Revise to read: Drop is 6 ft (1.8 m) 5-20 Table 5-5 top formulas for U.S. Customary and Metric read: ( ) 2 12 200 2 hh SLL S A + = Revise to read: ( ) 2 2 12 when 100 2 2 AS L hh = +5-21, 5-22 Figure 5-8, the notes at the bottom of the U.S. Customary and Metric tables
7、 read: Shaded area represents S = L The Metric cell for A = 5 and S = 55 (i.e., value = 54) reads: 54 Revise to read: Shaded area represents S L Revise to read: 54 without shading 5-23 Table 5-6, the bottom formulas for U.S. Customary and Metric read: 1 1 cos 28.65 R R HSO HSO R = Revise to read: 1
8、cos 28.65 R R HSO S R = 5-36 Table 5-8, the definition for term “a i ” for U.S. Customary and Metric reads: U.S. Customary a i= motorist deceleration rate (ft/s 2 ) in intersection approach when braking to a stop is not initiated (assume -5.0 ft/s 2 ) Metric a i= motorist deceleration rate (m/s 2 )
9、in intersection approach when braking to a stop is not initiated (assume -1.5 m/s 2 ) Revise to read: U.S. Customary a i= motorist deceleration rate (ft/s 2 ) on intersection approach when braking to a stop is not initiated (assume 5.0 ft/s 2 ) Metric a i= motorist deceleration rate (m/s 2 ) on inte
10、rsection approach when braking to a stop is not initiated (assume 1.5 m/s 2 ) Guide to Bicycle Facilities, 4th Edition 3-4 User Type Feature Dimension U.S. Customary Metric Recumbent bicyclist Physical length 82 in. 2.2 m Eye height 46 in. 1.2 m Tandem bicyclist Physical length (typical dimension) 9
11、6 in. 2.4 m Bicyclist with child trailer Physical width 30 in. 0.75 m Physical length 117 in. 3.0 m Hand bicyclist Eye height 34 in. 0.9 m Inline skater Sweep width 60 in. 1.5 m As with bicycle dimensions, bicyclist performance can vary considerably based upon operator ability and vehicle design. Ta
12、ble 3-2 lists various performance criteria for typical upright adult bicyclists as well as key performance criteria for other types of bicyclists (1), (4), (11). Bicyclist speeds vary based on age and ability and are a function of many factors, including bi- cyclist skill, bicyclist physical and cog
13、nitive abilities, bicycle design, traffic, lighting, wind condi- tions, transportation facility design, and terrain. Adults typically ride at 815 mph (1324 km/h) on level terrain, while children ride more slowly. Experienced, physically fit riders can ride up to 30 mph (50 km/h); very fit riders can
14、 ride at speeds in excess of 30 mph (50 km/h) but will typi- cally only ride at such speeds on roads. Table 3-2. Key Performance Criteria Bicyclist Type Feature Value U.S. Customary Metric Typical upright adult bicyclist Speed, paved level terrain 815 mph 1324 km/h Speed, downhill 2030 plus mph 32-5
15、0 plus km/h Speed, uphill 512 mph 8-19 km/h Perception reaction time 1.02.5s 1.02.5s Acceleration rate 1.55.0 ft/s 2 0.51.5 m/s 2 Coefficient of friction for braking, dry level pavement 0.32 0.32 Coefficient of friction for braking, wet level pavement 0.16 0.16 Deceleration rate (dry level pavement)
16、 810 ft/s 2 2.43 m/s 2 Deceleration rate for wet conditions (5080% reduction in efficiency) 25 ft/s 2 0.61.5 m/s 2 Recumbent bicyclist Speed, level terrain 1118 mph 1829 km/h Acceleration rate 3.06.0 ft/s 2 1.01.8 m/s 2 Deceleration rate 10.013.0 ft/s 2 3.04.0 m/s 2 Note: The speeds reported are for
17、 bicyclists on shared use paths. Experience suggests that maximum speeds on roadways can be considerably higher.Table 3-1. Key Dimensions (continued) 2012 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.Chap
18、ter 5: Design of Shared Use Paths 5-7 SyRl SyRl SyRl Figure 5-3. Safety Rail Between Path and Adjacent Slope 2012 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.Guide to Bicycle Facilities, 4th Edition 5-20
19、 Research indicates that, under dry conditions, the coefficient of friction of various other path us- ers range from 0.20 for inline skaters to 0.30 for recumbent bicyclists. If users with lower coeffi- cients of friction such as inline skaters or recumbent bicyclists are expected to make up a relat
20、ively large percentage of path users, stopping sight distances should be increased. For two-way shared use paths, the sight distance in the descending direction, that is, where “G” is defined as negative, will control the design. Figure 5-8 is used to select the minimum length of vertical curve need
21、ed to provide minimum stopping sight distance at various speeds on crest vertical curves. The eye height of the typi- cal adult bicyclist is assumed to be 4.5 ft (1.4 m), and the object height is assumed to be 0 in. (0 mm) to recognize that impediments to bicycle travel exist at pavement level. The
22、minimum length of vertical curve can also be calculated using the following equation as shown in Table 5-5. Table 5-5. Length of Crest Vertical Curve to Provide Sight Distance U.S. Customary Metric where: where: L = minimum length of vertical curve (ft) L = minimum length of vertical curve (m) A = a
23、lgebraic grade difference (percent) A = algebraic grade difference (percent) S = stopping sight distance (ft) S = stopping sight distance (m) h 1 = eye height (4.5 ft for a typical bicyclist) h 1 = eye height (1.4 m for a typical bicyclist) h 2 = object height (0 ft) h 2 = object height (0 m) 2012 b
24、y the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.Chapter 5: Design of Shared Use Paths 5-21 U.S. Customary A S = Stopping Sight Distance (ft) (%) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 2 30 70
25、 110 150 3 20 60 100 140 180 220 260 300 4 15 55 95 135 175 215 256 300 348 400 5 20 60 100 140 180 222 269 320 376 436 500 6 10 50 90 130 170 210 267 323 384 451 523 600 7 31 71 111 151 191 231 311 376 448 526 610 700 8 8 48 88 128 168 208 248 356 430 512 601 697 800 9 20 60 100 140 180 220 260 400
26、 484 576 676 784 900 10 30 70 110 150 190 230 270 444 538 640 751 871 1000 11 38 78 118 158 198 238 278 489 592 704 826 958 1100 12 5 45 85 125 165 205 245 285 533 645 768 901 1045 1200 13 11 51 91 131 171 211 251 291 578 699 832 976 1132 1300 14 16 56 96 136 176 216 256 296 622 753 896 1052 1220 14
27、00 15 20 60 100 140 180 220 260 300 667 807 960 1127 1307 1500 16 24 64 104 144 184 224 264 304 711 860 1024 1202 1394 1600 17 27 67 107 147 187 227 267 307 756 914 1088 1277 1481 1700 18 30 70 110 150 190 230 270 310 800 968 1152 1352 1568 1800 19 33 73 113 153 193 233 273 313 844 1022 1216 1427 16
28、55 1900 20 35 75 115 155 195 235 275 315 889 1076 1280 1502 1742 2000 21 37 77 117 157 197 237 277 317 933 1129 1344 1577 1829 2100 22 39 79 119 159 199 239 279 319 978 1183 1408 1652 1916 2200 23 41 81 121 161 201 241 281 321 1022 1237 1472 1728 2004 2300 24 3 43 83 123 163 203 243 283 323 1067 129
29、1 1536 1803 2091 2400 25 4 44 84 124 164 204 244 284 324 1111 1344 1600 1878 2178 2500 Shaded area represents S L Minimum length of vertical curve = 3 ft Figure 5-8. Minimum Length of Crest Vertical Curve Based on Stopping Sight Distance 2012 by the American Association of State Highway and Transpor
30、tation Officials. All rights reserved. Duplication is a violation of applicable law.Guide to Bicycle Facilities, 4th Edition 5-22 Metric A S = Stopping Sight Distance (m) (%) 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 2 10 20 30 40 50 60 3 7 17 27 37 47 57 67 77 87 97 107 4 0 10 20 30
31、 40 50 60 70 80 91 103 116 129 143 5 4 14 24 34 44 54 64 75 88 100 114 129 145 161 179 6 3 13 23 33 43 54 65 77 91 105 121 137 155 174 193 214 7 10 20 30 40 51 63 76 90 106 123 141 160 181 203 226 250 8 5 15 25 35 46 58 71 86 103 121 140 161 183 206 231 258 286 9 9 19 29 39 51 65 80 97 116 136 158 1
32、81 206 232 260 290 321 10 2 12 22 32 44 57 72 89 108 129 151 175 201 229 258 289 322 357 11 5 15 25 35 48 63 80 98 119 141 166 193 221 251 284 318 355 393 12 7 17 27 39 53 69 87 107 130 154 181 210 241 274 310 347 387 429 13 8 18 29 42 57 74 94 116 140 167 196 228 261 297 335 376 419 464 14 10 20 31
33、 45 61 80 101 125 151 180 211 245 281 320 361 405 451 500 15 1 11 21 33 48 66 86 108 134 162 193 226 263 301 343 387 434 483 536 16 3 13 23 36 51 70 91 116 143 173 206 241 280 321 366 413 463 516 571 17 4 14 24 38 55 74 97 123 152 184 219 257 298 342 389 439 492 548 607 18 4 14 26 40 58 79 103 130 1
34、61 194 231 272 315 362 411 464 521 580 643 19 5 15 27 42 61 83 109 137 170 205 244 287 333 382 434 490 550 612 679 20 6 16 29 45 64 88 114 145 179 216 257 302 350 402 457 516 579 645 714 21 7 17 30 47 68 92 120 152 188 227 270 317 368 422 480 542 608 677 750 22 7 18 31 49 71 96 126 159 196 238 283 3
35、32 385 442 503 568 636 709 786 23 8 18 33 51 74 101 131 166 205 248 296 347 403 462 526 593 665 741 821 24 8 19 34 54 77 105 137 174 214 259 309 362 420 482 549 619 694 774 857 25 9 20 36 56 80 109 143 181 223 270 321 377 438 502 571 645 723 806 893 Shaded area represents S L Minimum length of verti
36、cal curve = 1 m Figure 5-8. Minimum Length of Crest Vertical Curve Based on Stopping Sight Distance (continued) Other path users such as child bicyclists, hand bicyclists, recumbent bicyclists, and others have lower eye heights than a typical adult bicyclist. Eye heights are approximately 2.6 ft (0.
37、85 m) for hand bicyclists and 3.9 ft (1.2 m) for recumbent bicyclists. When compared to the eye heights of typical bicyclists, these lower eye heights limit sight distance over crest vertical curves. However, since most hand bicyclists and child bicyclists travel slower than typical adult bicyclists
38、, their needs are met by using the values in Figure 5-8. Recumbent bicyclists generally travel faster than typical upright bicyclists, so if they are expected to make up a relatively large percentage of path users, crest vertical curve lengths should be increased accordingly (operating characteristi
39、cs of recumbent bicyclists are found in Chapter 3). Figures 5-9, 5-10, and Table 5-6 indicate the minimum clearance that should be used for line-of- sight obstructions for horizontal curves. The lateral clearance (horizontal sight line offset or HSO) is obtained by using the table in Figure 5-9 with
40、 the stopping sight distance (Figure 5-6) and the proposed horizontal radius of curvature. Path users typically travel side-by-side on shared use paths. On narrow paths, bicyclists have a tendency to ride near the middle of the path. For these reasons, and because of the higher likeli- 2012 by the A
41、merican Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.Chapter 5: Design of Shared Use Paths 5-23 hood for crashes on curves, lateral clearances on horizontal curves should be calculated based on the sum of the stopping si
42、ght distances for path users traveling in opposite directions around the curve. Where this is not practical, consideration should be given to widening the path through the curve, installing a yellow center line stripe, installing turn or curve warning signs (W1 series) in accordance with the MUTCD (
43、7), or a combination of these alternatives. See Sections 5.4.1 and 5.4.2 for more information about center line pavement markings and signs. Figure 5-9. Diagram Illustrating Components for Determining Horizontal Sight Distance Table 5-6. Horizontal Sight Distance U.S. Customary Metric where: where:
44、S = stopping sight distance (ft) S = stopping sight distance (m) R = radius of centerline of lane (ft) R = radius of centerline of lane (m) HSO = horizontal sightline offset, distance from centerline of lane to obstruction (ft) HSO = horizontal sightline offset, distance from centerline of lane to o
45、bstruction (m) Note: Angle is expressed in degrees; line of sight is 2.3 ft above centerline of inside lane at point of obstruction. Note: Angle is expressed in degrees; line of sight is 0.7 m above centerline of inside lane at point of obstruction. 2012 by the American Association of State Highway
46、and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.Guide to Bicycle Facilities, 4th Edition 5-36 Table 5-8. Length of Path Leg of Sight Triangle U.S. Customary Metric + 1.47 1.47 0.88 1.47 eb a i a ga g VV t = a w+L t =t V b= V t road path + 0.278 0.278 0
47、.167 0.278 eb a i a ga g VV t = a w+L t =t V b= V t road path where: where: t g = travel time to reach and clear the path (s) t g = travel time to reach and clear the path (s) b = length of leg sight triangle along the path approach (ft) b = length of leg sight triangle along the path approach (m) t
48、 a = travel time to reach the path from the decision point for a motorist that doesnt stop (s). For road approach grades that exceed 3 percent, value should be adjusted in accordance with AASHTOs A Policy on Geomet- ric Design of Highways and Streets (5) t a = travel time to reach the path from the decision point for a motorist that doesnt stop (s). For road approach grades that exceed 3 percent, value should be adjusted in accord
