ML20090J985
| ML20090J985 | |
| Person / Time | |
|---|---|
| Site: | Shoreham File:Long Island Lighting Company icon.png |
| Issue date: | 02/23/1984 |
| From: | NATIONAL ACADEMY OF SCIENCES |
| To: | |
| References | |
| A-011, A-11, NUDOCS 8405230468 | |
| Download: ML20090J985 (2) | |
Text
ha = ll 4 /t Ce (5K Y0
(,.
I..L1.-l..IG..%.4.2.?.e 00.s(.y.E T EE.
TRANSPORTATION
""- 2,t" a,',;,:
1 O
RESEARCH
'84 ER 19 P5 53 CIRGBstAR Transportation Research Board, National Academy of Sciences,2101 Constitution Avenue, Washington, D.C. 20418 INTERIM MATERIALS ON
-d" 1 highway transportation HIGHWAY CAPACITY 2--
5 other sub;ect areas 12 plannmg 21 facihtees design 54 operations and traffic control 55 traffic flow, capacity, and momurements O
o....cu, away c
.s.
EXNWTNo.
II App 4 cant
/ Staff Intervenor identified Rec'ved Rejected Dite: -
OID3 9Y ne,eaw ' unaxu Amen n 6
l O
ggggagetaaja,g o
Q i
J
)
a Critic:1 Movern:nt Andysis 1
I estimating capacity,and includes a numerical to establish a capacity value for any intersection exm plo. -
sppmach or lano eithout explicitly defining each The computations in Table 1 irn11cate that very rmdifying factor.
little variation exists in the value used for 1.
Inno Width. 'Ihe critical novent pmcedure l
capacity of a stantarvi 12 foot wide (3.7 m) lane at ggp ggger and Fanbro (5) includte a reduc-y an tuten nignalind intersoction with ideal tra f fic tion in de% 1 capacity of 10 percent for lano j
corditions (no trucka, inem, or turning motions).
vidths betwen 9.0 and 9.9 feet (2.7 m and 3.0 m).
Three of the models shosn give capacities of For lanos 10.0 feet (3.0 m) or wichir, no actatment approximate ly D00 pch for a greert tiw/ cycle tire in ca,acity is nude. Note that thme adjustnrnts (G/C) rutto of 0.5.
The British trcthod, thich has hrease the passeru;er car witre (ICV) rather than i
been known to givo considerably higher cmputed tuuce capacity.
I values for capacity than North America rnethods' dhing the Australian procedures (9.
10),
shows a computed capacity 12 percent higter. The enpacity adjuatrients are made for lanos not falTing 1%'s 1101 yields a raracity value of 805 pch (G/C =
in th s 10.0 to 12.0 foot (3.0 m to 3.7 m) range.
0.00). or atout 10% below the other nastis.ds.
U tments for the value of capacity are:
f Because of the close agreement between Derry-6talhi (H), Cy>1lo-pinnell (2), hwer-Fachm (5), and Bellis-Reilly ( H, 12, 13), an averago Lane Width feet):
8.0 9.0 13.0 14.0 15.0 i
valun of 18co_pascenger cars oer Tourf Reer!
Lane Width reters):
2.4 2.7 4.0 4.3 4.6 1
f l
1pc_hn for a 12 foot (3.7 m) through traffic
)
g g g g g lane--with no truckn, buses, turns, or gutestrian interference--can be used as a base value for
, lication of the 1965 llCM, with the assumed capacity in the critical movement analysis y oditions tami in Table 1, givm adjustrent values I
of - M for h $ valent of a D foot (2.7 Ir.) lane l
technique. It should be noted that the British capacity prrodurus use--for a 13 foot (4.0 m) wide and + lifi for the (quivalent of a 14 foot (4.3 m) lano-a carncity of IRO pehg.
lane. Table 2 combines these concepts into a The f actors which are considered of prim" M 1y applied set of valum. h we aM uste nts innrtance in nulifying the capacity value of 1600 rely principally on the Mos.cr-Facbro work, but p hg for a utngle 12 foot (3.7 m) Inne are as include upward adjustments in capacity for wide traific lanm as ineluded in enest other n)thods.
I M"
One irportant concept to note is that under Intk 1.
Inno Width traffic con 11tions, lam widths in the 10 to 13 foot (3.0 to 4.0 m) rango have little effect on
,2 '
UU*" "#"I TI" saturation flow or capacity. Ilowever, it is likely i
that if unfort and safety scro to tu considered in '
.J. Bus Stop Operations intersection level of service (IDS), lane width dif ferences wmld tave a s;reater inact cm IDS than 4.
Icit Turns tiry will in tre pmpomi rww IKR with its emphasis on mbility ratter than quality of flow.
S.
Right Turns ard hdestrian Activity 2.
Bunos and Trucks. Trucks, and buses not 6.
htrking Activity L..vir g a designated stop at the interancticn under wlysios (callut "thruath" buses), reduce capacity
.{
7.
haking daracteristics (nsk lkur Factor) uecause tte tint hemhay of them vehicim tends to to longer than tic 2.0 second average implied by a Other factors-such as vertical grade and type ut caracit/ set at 1800 pchg.
driver ustrg: tic interwetion-41ay le of imortanct There are two nuns available for including the
(.
in nutifying tre cancity vrtlun, but little surarch of fects of trucks armi tuses. First, each tnack or ll has been acempitsho! in these areas. Also, field bua can tm) converted to an equivalent number of i
l numment of naturntion flow allons the IKN user passenger cars, an! tte voltre used in the analysis i,
i Table 2. Lane Width Adjustments Ad.jusyoqt racdo,r_s to Capacity for fane Width (ft.)
Referenco u
9 10 T1 12 13 14 15 16 De r ry-Gandhi (B)
(Suwost use of Australian factors)
Mussor-Fambro Q)
NA" 1.10 1.00 1.00 1.00 1.00 1.00 1.00 NA b
Australian (9), (10) 1.12 1.07 1.00 1.00 1.00 0.97 0.96 0.94 C
Rocommended 8.0-9.9 feet 10.0 -12.9 feet 13.0-15.9 feet Adjustmont g, 3, g--
g, 3,yo W = 0.90 Factors
- NA denotes data not available.
I'For 16-foot wide approaches, two 8-foot lanos would be.nssumed.
f
" Recommended for use in Critical Movement Analysis (OPEPATIONS AND DESIGN Application, Stop 8)
Sources As cited abovo and W.R.
Reilly (NCllRP Project 3-28)
(1 foot =.305 meter)
.L
.__A.._.-.
_ _ _ _ _