36:
150:
109:
218:(PRT), and maneuver time (MT). Perception-reaction time is the time it takes for a road user to realize that a reaction is needed due to a road condition, decide what maneuver is appropriate (in this case, stopping the vehicle), and start the maneuver (taking the foot off the accelerator and depressing the brake pedal). Maneuver time is the time it takes to complete the maneuver (
518:...the distance required by the user, traveling at a given speed, to bring the vehicle or bicycle to a stop after an object ½-foot high on the road becomes visible. Stopping sight distance for motorists is measured from the driver's eyes, which are assumed to be 3½ feet above the pavement surface, to an object ½-foot high on the road. ...
381:
A deceleration rate of 3.4 m/s (11.2 ft/s) is used to determine stopping sight distance. Approximately 90 percent of all drivers decelerate at rates greater than that. These values are within most drivers' ability to stay within his or her lane and maintain steering control. Also, most wet
288:
Based on the results of many studies, 2.5 seconds has been chosen for a perception-reaction time. This time will accommodate approximately 90 percent of all drivers when confronted with simple to moderately complex highway situations. Greater reaction time should be allowed in situations that are
232:
The values of stopping sight distance used in design represent a near worst-case situation. For design, a conservative distance is needed to allow a vehicle traveling at design speed to stop before reaching a stationary object in its path. A generous amount of time is given for the
203:. It is a near worst-case distance a vehicle driver needs to be able to see in order to have room to stop before colliding with something in the roadway, such as a pedestrian in a crosswalk, a stopped vehicle, or
226:
233:
perception-reaction process, and a fairly low rate of deceleration is used. The design sight distance allows a below-average driver to stop in time to avoid a collision in most cases.
46:
522:
sight distance greater than stopping sight distance is desirable to allow drivers time for decisions without making last minute erratic maneuvers...
640:
80:
382:
pavement surfaces and most vehicle braking systems are capable of providing enough braking force to exceed this deceleration rate.
447:
58:
62:
200:
196:
669:
222:). The distance driven during perception-reaction time and maneuver time is the sight distance needed.
162:
121:
467:
208:
472:
215:
627:
636:
531:
375:
214:
Stopping sight distance is the distance traveled during the two phases of stopping a vehicle:
601:
452:
219:
176:
94:
654:
546:
495:
371:
663:
462:
457:
496:"Chapter 200 Geometric Design and Structure Standards, Topic 201 – Sight Distance"
158:
117:
229:(AASHTO) allow 1.5 seconds for perception time and 1.0 second for reaction time.
17:
523:
204:
560:
370:
Actual braking distances are affected by the vehicle type and condition, the
587:
573:
American
Association of State Highway and Transportation Officials (1994)
635:. Transportation Research Board (National Academy Press). p. I-13.
157:
Graphs are unavailable due to technical issues. There is more info on
116:
Graphs are unavailable due to technical issues. There is more info on
227:
American
Association of State Highway and Transportation Officials
93:"Stopping distance" redirects here. The term may also refer to
143:
102:
29:
629:
NCHRP Report 400: Determination of
Stopping Sight Distances
388:(SSD) is the sum of reaction distance and braking distance
505:. California Department of Transportation. pp. 200_1
207:. Insufficient sight distance can adversely affect the
185:
against baseline braking distance with good conditions.
183:
This plots the engineered worst case stopping scenario,
54:
626:
575:
A Policy on
Geometric Design of Highways and Streets
272:= driver perception-reaction distance, m (ft)
43:The examples and perspective in this article
8:
211:or operations of a roadway or intersection.
602:"Brake Reaction Times of Unalerted Drivers"
524:Read more types at CA Highway Design Manual
81:Learn how and when to remove this message
561:"Tables of speed and stopping distances"
490:
488:
484:
588:Human Factors: Perception and Reaction
541:
540:
529:
134:Comparison of sight distances by type
27:Type of sight distance in road design
7:
237:Driver perception/reaction distance
655:Wikibooks: Stopping Sight Distance
25:
284:= brake reaction time, in seconds
220:decelerating and coming to a stop
175:Comparison of stopping sight to
148:
107:
34:
600:Taoka, George T. (March 1989).
366:= deceleration rate, m/s (ft/s)
378:, and numerous other factors.
1:
448:Assured clear distance ahead
225:The design standards of the
374:of the road, the available
195:is one of several types of
57:, discuss the issue on the
686:
360:= design speed, km/h (mph)
354:= braking distance, m (ft)
278:= design speed, km/h (mph)
92:
563:. The State of Virginia.
258:= 1.47 Vt (US customary)
216:perception-reaction time
520:Decision Sight Distance
516:Stopping Sight Distance
386:Stopping sight distance
193:Stopping sight distance
503:Highway Design Manual
63:create a new article
55:improve this article
45:may not represent a
468:Road traffic safety
249:= 0.278 Vt (metric)
586:Joseph E. Badger,
473:Traffic psychology
295:is calculated by:
239:is calculated by:
539:External link in
408:SSD = 0.278 Vt +
170:
169:
129:
128:
91:
90:
83:
65:, as appropriate.
18:Stopping distance
16:(Redirected from
677:
647:
646:
634:
623:
617:
616:
606:
597:
591:
584:
578:
571:
565:
564:
557:
551:
550:
544:
543:
537:
535:
527:
512:
510:
500:
492:
453:Braking distance
436:
435:
431:
424:SSD = 1.47 Vt +
420:
419:
415:
339:
338:
334:
317:
316:
312:
293:Braking distance
152:
151:
144:
111:
110:
103:
95:Braking distance
86:
79:
75:
72:
66:
38:
37:
30:
21:
685:
684:
680:
679:
678:
676:
675:
674:
660:
659:
651:
650:
643:
632:
625:
624:
620:
604:
599:
598:
594:
585:
581:
572:
568:
559:
558:
554:
538:
528:
508:
506:
498:
494:
493:
486:
481:
444:
433:
426:
425:
417:
410:
409:
405:
398:
353:
336:
329:
328:
326:
314:
307:
306:
304:
271:
257:
248:
190:
189:
188:
187:
184:
181:
171:
166:
153:
149:
139:
138:
137:
136:
130:
125:
112:
108:
98:
87:
76:
70:
67:
52:
39:
35:
28:
23:
22:
15:
12:
11:
5:
683:
681:
673:
672:
670:Road transport
662:
661:
658:
657:
649:
648:
641:
618:
592:
579:
566:
552:
483:
482:
480:
477:
476:
475:
470:
465:
460:
455:
450:
443:
440:
439:
438:
437:(US customary)
422:
406:
403:
396:
368:
367:
361:
355:
351:
342:
341:
340:(US customary)
324:
319:
302:
289:more complex.
286:
285:
279:
273:
269:
260:
259:
255:
250:
246:
197:sight distance
173:
172:
168:
167:
156:
154:
147:
142:
141:
140:
132:
131:
127:
126:
115:
113:
106:
101:
100:
99:
89:
88:
49:of the subject
47:worldwide view
42:
40:
33:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
682:
671:
668:
667:
665:
656:
653:
652:
644:
642:0-309-06073-7
638:
631:
630:
622:
619:
614:
610:
603:
596:
593:
589:
583:
580:
577:(pp. 117–118)
576:
570:
567:
562:
556:
553:
548:
533:
526:
525:
521:
517:
504:
497:
491:
489:
485:
478:
474:
471:
469:
466:
464:
463:Reaction time
461:
459:
456:
454:
451:
449:
446:
445:
441:
430:
423:
414:
407:
402:
395:
391:
390:
389:
387:
383:
379:
377:
373:
365:
362:
359:
356:
350:
347:
346:
345:
333:
323:
320:
311:
301:
298:
297:
296:
294:
290:
283:
280:
277:
274:
268:
265:
264:
263:
254:
251:
245:
242:
241:
240:
238:
234:
230:
228:
223:
221:
217:
212:
210:
206:
202:
198:
194:
186:
180:
178:
177:total braking
164:
163:MediaWiki.org
160:
155:
146:
145:
135:
123:
122:MediaWiki.org
119:
114:
105:
104:
96:
85:
82:
74:
64:
60:
56:
50:
48:
41:
32:
31:
19:
628:
621:
612:
608:
595:
582:
574:
569:
555:
542:|quote=
519:
515:
514:
507:. Retrieved
502:
458:Design speed
428:
412:
400:
393:
385:
384:
380:
369:
363:
357:
348:
343:
331:
321:
309:
299:
292:
291:
287:
281:
275:
266:
261:
252:
243:
236:
235:
231:
224:
213:
192:
191:
182:
174:
133:
77:
71:October 2012
68:
44:
615:(3): 19–21.
609:ITE Journal
205:road debris
201:road design
159:Phabricator
118:Phabricator
479:References
179:distances
59:talk page
664:Category
590:, at 1–2
532:cite web
442:See also
421:(metric)
376:traction
318:(metric)
199:used in
53:You may
509:12 July
432:⁄
416:⁄
372:incline
344:where:
335:⁄
327:> =
313:⁄
262:Where:
161:and on
120:and on
639:
427:1.075
411:0.039
392:SSD =
330:1.075
308:0.039
209:safety
633:(PDF)
605:(PDF)
499:(PDF)
61:, or
637:ISBN
547:help
511:2018
397:PRT
270:PRT
256:PRT
247:PRT
666::
613:59
611:.
607:.
536::
534:}}
530:{{
513:.
501:.
487:^
404:MT
399:+
352:MT
325:MT
305:=
303:MT
645:.
549:)
545:(
434:a
429:V
418:a
413:V
401:d
394:d
364:a
358:V
349:d
337:a
332:V
322:d
315:a
310:V
300:d
282:t
276:V
267:d
253:d
244:d
165:.
124:.
97:.
84:)
78:(
73:)
69:(
51:.
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.