30 4 2013 4 Journal of Hghway and Transportaton Research and Development Vol. 30 No. 4 Apr. 2013 do10. 3969 /j. ssn. 1002-0268. 2013. 04. 018 1 1 2 1. 4000742. 201804 2 U491. 1 + 3 A 1002-0268 201304-0101 - 06 A Method for Determnng Servce Level of Road Network Based on Improved Capacty Model GUO Janng 1 LIU We 1 ZHANG Xn 2 1. School of TransportChongqng Jaotong UnvertyChongqng 400074Chna 2. School of Transport EngneerngTongj UnverstyShangha 201804Chna AbstractIn order to evaluate the servce level of urban road network more concsely and avod tradtonal complcated process the method for determnng the servce level s mproved. The basc model based on the servce level of road network capacty s ntroduced. Consderng the nfluence of tme and space on resources the model s mproved. Based on the mproved model and the actual traffc demand ratothe ranges of speed correspondng to each level of servce are calculated. Accordng the actual operatng condtons of an urban road networkthe servce level of the road network s evaluated wth the tradtonal method and the speed range modeland the results are compared. The example shows that the speed range model s accurate and more ntutve for the evaluaton. Key wordstraffc engneerngspeed rangecapacty calculaton modelservce level of road network road network state assessment 0 4 1-2 5-6 Ford - Flukson 3 ECS 7 2012-10 - 29 CSTC2011CX - RKXB0023 1990 -. 464296781@ qq. com
102 30 1. 2 6 10-11 8 1 = K L μ 1 λ 0 λ 0 V /C K = 1 2 3 4 L μ 1K 1 λ 0 0. 9 7 K λ 0 = λ 0 C 0 / v 0 1-0. 94λ 0 2 K λ 0 λ 0 C 0 v 0 2L 1 L 1. 1 L = 4 l m 1 m 2 m 3 m 4 3 = 1 L l m 1 8-9 m 2 m 3 m 4 V /C V /C V /C = λ 0 1 1 Tab. 1 Servce levels of road network m 3 A B C D E F λ 0 <0.4 0.4 ~0.6 0.6 ~0.75 0.75 ~0.9 0.9 ~1.0 >1.0 1 2 3
4 103 Tab. 2 2 Correcton factors of lane seral numbers 1 2 3 4 5 m 2 1. 00 0. 80 ~ 0. 89 0. 65 ~ 0. 68 0. 50 ~ 0. 65 0. 40 ~ 0. 50 veh t mn veh t mn veh t mn 1 d 3 a 24 60 4 t 3 Tab. 3 Reducton factors λ 0 1 d 4 m 3 0. 75 0. 80 0. 85 0. 9 m 4 0. 9 0. 6 0. 6 0. 5 1 d 3 3μ 9% ~ 10% 10% Cλ 0 10% C λ 0 μ 4 4 Tab. 4 Recommended comprehensve utlzaton coeffcents of road space and tme resources 2 0. 75 0. 55 ~ 0. 60 0. 40 ~ 0. 45 0. 30 ~ 0. 35 1. 3 2. 1 - - 1 d 24 h 1 1 veh t mn 12 v = v 0 1 + αv /C β 6
104 30 v v 0 α β 6 13 1 2. 2 2 2 1 r λ 0 = 2 1 v V /C h s h s = 1 000 v 7 N λ 0 h s v N 5 B C D 3 r = h s t 8 B C D 3 r t D D 4 3 C = S r 1 000 9 C S 66. 7 10 4 veh 1 33. 3 mn 5 5 p = C 4 = 1 C 10 p 2. 3 - = p 11 λ 0 3 2 h λ 0 s S = rλ0 t 12 13 4 3 2 v λ 0 = N λ 0 h λ0 s 1 000 14 v λ 0 λ 0 1 5 Tab. 5 Basc data of urban roads /km h - 1 64. 50 28. 39 23. 76 15. 42 /km 1 201. 59 1 137. 27 1 510. 17 1 542. 15 /km h 1 201. 59 1 137. 27 1 510. 17 1 542. 15
4 105 5 6 0. 12 Tab. 6 Capacty n dfferent servce levels 0. 21 0. 30 0. 37 6 7 λ K /veh km -1 ln -1 /veh 0 Tab. 7 7 B 0. 6 26 17 27 29 2 734 606 273 461 C 0. 7 38 25 40 43 4 067 260 406 726 D 0. 8 60 39 62 68 6 410 152 641 015 Crtcal vehcle speeds n dfferent servce levels B C D / / /km h / / / / veh km h - 1 veh km h - 1 veh km h - 1 1 201. 59 33 335 63. 99 49 581 55. 62 78 141 41. 44 1 137. 27 56 581 33. 51 84 155 24. 04 132 631 16. 05 1 510. 17 82 370 27. 46 122 511 20. 59 193 082 14. 05 1 542. 15 101 174 18. 04 150 480 13. 25 237 161 8. 92 5 391. 17 273 461 406 726 641 015 7 v 1 63. 99 km /h v 2 33. 51 km /h v 3 27. 46 km /h v 4 18. 04 km /h B 63. 99 km /h v 1 55. 62 km /h 33. 51 km /h v 2 24. 04 km /h 27. 46 km /h v 3 20. 59 km /h 18. 04 km /h v 4 13. 25 km /h C 4 55. 62 km /h v 1 41. 44 km /h24. 04 km /h v 2 16. 05 km /h20. 59 km /h v 3 14. 05 km /h 13. 25 km /h v 4 8. 92 km /h D 1 Fg. 1 Road capacty n dfferent servce levels 1 1 2 C References 7 1. C 2 J. 200114 2 90 -
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