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GEOMETRIC DESIGN PROBLEM

Given Data:

Road section Route A-C-E: E-C-A

(vpd

Route A-!-E: E-!-A

(vpd!-A "#$#%%: "&$%%%

C-A '$%%%: '$%%%

A) Based from the given data, Road Sections C-A under Route A-C-E and K-A under

Route A-K-E gives the maximum traffic flows; hence adopt this value for the design ofthe two !" routes#

Expected Average Annual $ail% &raffic' (),))) and ((,*)) vehicles respectivel%

A-C-E + ,))); $$ + )#* A-K-E + *,*)) vehicles ; $$ + )#(

E-C-A + !,))); $$ + )#.( E-K-A + /,))) vehicles ; $$ + )#0*

B) Expected &raffic Composition

• *)1 of private cars and taxica2s will travel directl% from A-K-E and vice versa

• ()1 of private cars and taxica2s will travel from A-C3E and vice versa

• Big 2uses and mini2uses will travel from A-C-E and vice versa

• 4ea5 6our 7actor 467" + )#8

C) Expected Characteristics of the vehicles

&%pe of

vehicles

Expected

maximum speed5ph"

Average

Effective lengthm"

4assenger Car

E9uivalent

Average

width m"

4rivate car .) / !

&axica2 *) / #! !#

:ini2uses /) . # !#(

Big 2uses ) ! !# !#/

• ther $esign <nformation# Collection and dropping of passengers along the road!# &otal road length from A-E is )#0 5ilometers

(# !#1 average traffic growth per %ear for the past ) %ears

0# $esign %ear is %ears# Current AA$& are (),))) and ((,*)) vehicles

• Assumptions

# 4edestrians 7low + (,))) per hour per direction in the section of the road within

the 2uilt-up area

$# =evel of Service'

Reference' ta2le #/, >uide for Selection of $esign =evel of ServiceBoo5' A 4olic% on >eometric $esign of 6ighwa%s and Streets 880, American

Association of State 6ighwa% and &ransportation fficials#

6ighwa%&%pe

&%pes of Areas and Appropriate =evel of Service

Rural

=evel

Rural

Rolling

Rural

:ountainous

?r2an @

Su2ur2an

7reewa% B B C C

Arterial B B C C

Collector C C $ $

*e+ic,e Tpe P.opo.tion /,o0 in 14rivate Cars )

&axica2s !)

:ini2uses !)

Big 2uses )



=ocal $ $ $ $

&a2le# -/

B% ?sing the a2ove ta2le, from relation 2etween &%pe of Area and Appropriate =S for Rural Rolling Collector, LOS 2 C

Re3ui.ed Tas4s:") To desi5n t+e c.oss section o6 t+e .oad

) To desi5n t+e +o.i7onta, a,i5n8ent

9) To desi5n t+e ve.tica, a,i5n8ent

TAS! ": CROSS-SECTION DESIGN

a) C,assi6ication o6 .oad and con6i5u.ation o6 t+e c.oss section

• 4edestrians will 2e provided separate lanes

• Bus 2a%s will 2e provided for dropping and collecting passengers along the lin5

ACE along 2uilt up areas onl%) Dete.8ination o6 nu8e. o6 ,anes .e3ui.ed:

• Desi5n De8and /,o0 Rate (DD/R 6o. eac+ ve+ic,e tpe

$$7R m" + EAA$& x EK x 47m" x $$m" E467

where'EAA$& + forecast or assumed average annual average annual dail% traffic

EK + percentage of AA$& occurring during pea5 hour

)#! 3 )#!) for rural routes

and in this Case is assumed to 2e + )#!47m" + 4roportion of conve%or categor% m in a pea5 period traffic stream

$$m" + directional distri2ution factor + proportion of traffic of group

mD that moves in the maor direction )#.* for route A-C-E and + )#( forroute A-K-E as deduced from the highest traffic flow per da%

E467 + expected pea5 hour factor )#8

P.ivate Ca.s and ta;icas a,on5 Route A-!-E

Conside.in5 #%1 t.ansit ca.s and t.ave,,in5 6.o8 A to E and vice ve.sa on,)

47 car" + )# x )#* + )#(47 taxica2s" + )#! x )#* + )#0

$$7R car" + EAA$& x EK x 47car" x $$car"

E467

Fhere'EA$$& n+" + current AA$& x G ave#traffic growth factor per %ear"n"

+ ((,*)) x G !#1"

+ ((,*)) x #)!"

+ 0.#.). vehiclesSu2stituting all values,

$$7R car" + 0..). x )#! x )#( x )#( )#8

2 ""<< ca.s=+ou.

$$7R taxica2s 2 0..). x )#! x )#0 x )#(

)#8

2 <'>

!



/o. Bi5 uses$ Mini uses and 9%1 o6 p.ivate ca.s and ta;icas a,on5 Route A-

C-E

i) 9%1 P.ivate ca.s

47 m" + )#) x )#() + )#$$7R car" + EAA$& x EK x 47car" x $$car"

E467

Fhere'EA$$& n+" + current AA$& x G ave#traffic growth factor per %ear"n"

+ (),))) x G !#1"

+ (),))) x #)!"

+ 0(,0) vehiclesSu2stituting all values,

$$7R car" + 0(0) x )#! x )# x )#.(

)#82 &>9 ca.s=+ou.

ii) 9%1 Ta;icas

47 taxica2s" + )#!) x )#() + )#)/

$$7R taxica2s 2 0(0) x )#! x )#)/ x )#.(

)#8

2 #<

iii) Bi5 Buses

47 m" + )#)

$$7R 2ig 2uses" + 0(0) x )#! x )#) x )#.(

)#8

+ <'& i5 uses=+ou.

iv) Mini Buses

47 m" + )#!)

$$7R mini 2uses" + 0(0) x )#! x )#!) x )#.(

)#8

+ ?" 8iniuses=+ou.

v) Pedest.ian @a,40a Desi5n

7rom &a2le #(# Characteristics of =evel of Service on &raffic 7acilities, &%pical=evel of Service Criteria for Fal5wa%s, ?r2an Roads CharacteriHation $ata

Collection Anal%sis, 2% E# # A5in%emi# 7or

7low Rate +I )pedJminJft# for =evel of Service C

&his is e9uivalent to' ) x /) pedestrians J )#()m J hour

+ /)) + !,))) pedestrians J m Jhr

)#()&herefore in order to accommodate (,))) pedestriansJhrJdirection, the re9uired

width is given 2%'

Fidth of wal5wa% + (,))) x )#()

/)) x )#8

+ #*m

T+us p.ovide a ")'% 8ete.s 0ide 0a,40a in eac+ di.ection o6 t+e .oad a,on5

Route A-C-E)

Desi5n Se.vice /,o0 Rate

(



Dete.8ination o6 Nu8e. o6 Lanes to cate. 6o. t+e tpes o6 ve+ic,es :

P.ivate ca.s on, a,on5 A-!-E .oute

DD/R: $$7R car + /(0 x #) +00 pcph

$$7R taxica2s + 0. x #! + ) pcph/80 pcph

• Desi5n Speed

*d 2 Min * (t.a66ic * (te..ain ))e3uation )

where'

d + desira2le design speed of the road sectiontraffic" + RS 3 A

RS + speed environment i#e# expected .th percentile desired speed

or the expected maximum average running speed

A + factor of safet%; ) to 5ph if RS L+ ))5ph,) if RS I )) 5ph

terrain" + recommended design 2ased on terrain consideration as in&a2le !#! page !#*

Mote' sometimes terrain or other site conditions ma% not permit the useof design speed 2ased on the a2ove concept# 6owever, whatever

the conditions, the difference 2etween the design speeds of two

adacent sections must not 2e greater than 5ph#

&herefore'

*d 2 * (t.a66ic

2 )#)x )#* G )#!) x )#*) J 47cJc G 47taxica2s J taxica2s

+ )#08 J )#(J.) G )#0J*)

+ */#./; sa% ## 4p+

6ence, for a level of service C, the desira2le speed range is' ?max + .5ph to ?max +

!5ph;i#e# in the range /85ph 3/5ph# &hus, the minimum desira2le speed that

corresponds to the $esign Service flow rate is /5ph#

7rom the e9uation which relates the service flow rate 9"; corresponding design speed

?9"; Capacit% C"; 4roportion 7lows of various vehicle t%pes 47m" and $esira2ledesign speed'

?9 + )#8!JΣ{47mJ?maxm"N G ((#/9JC 3 00#/ 9JC!, in this case ?max

+ d + **5ph

Su2stituting the design values, it follows that'

/ + )#8! x 77 G ((#/9JC 3 00#/ 9JC!

B% 9uadratic E9uation; 9JC + )#8)

Idea, /,o0 Rate:

Assuming the capacit% of the lane to 2e !,))pcphplActual capacit% of the lane due to mixed traffic + <deal capacit% x ft

7t, is given 2% the e9uation' JΣ47m" x 4CEm)]

= 1

O )#(J)#08PN G O)#0J)#08P#!N"

2 %)?'

6ence, the actual capacit% is' )#8 x !)) + 88

&herefore the $esign Service 7low Rate, $S7R + )#8) x 88

0



+ *8/pcphpl

Nu8e. o6 ,anes: 2 $$7R

$S7R

Su2stituting all values; + /80

*8/

2 )#80; sa% " ,ane pe. di.ection

One (" ,ane in eac+ di.ection is .e3ui.ed in o.de. to acco88odate t+e p.evai,in5

Desi5n De8and T.a66ic 6,o0 6o. #%1 p.ivate ca.s and ta;icas on,)

Desi5n C.oss Section

Lane @idt+:

i) Mini8u8 @idt+ o6 a T.a66ic Lane

F=dmin + Fv G Slm G Sf

where'

F=dmin + minimum desira2le width of vehicle traffic lane

Fv + width of design vehicle; taxica2 + !#) meters

Slm + space re9uired for lateral movements, )#)-#)m" for speed L+*)5ph

+ )#)m

Slf + space re9uired due to fear of sidewal5 or o2ects, )#.-#)m" for speedL+*)5ph

+ )#.)m

Su2stituting all values,

F=dmin + !#) G )#) G )#.)

+ 9)<% 8ete.s

ii) Road ca8e.

&%pe of pavement is assumed to 2e Asphalt 2ituminous" Concrete# &hus a cross 3

fall of )'1 is to 2e provided#

iii) D.aina5e

4rovide "8 wide drainage

Tota, Ri5+t o6 @a 0idt+ .e3ui.ed as p.oposed is:

• S+ou,de. 2 ")' 8 ; 2 9)%%

• Mao. ,anes 2 9)< 8 ; 2 &)>%

• D.aina5e 2 ")% 8 ; 2 )%%

Tota, Re3ui.ed @idt+ 2 "")>% 8ete.s

Tas4

Gene.a, Desi5n o6 Fo.i7onta, cu.ves

Route A-!-E:

• Esta,is+in5 t+.es+o,d va,ues:

Mini8u8 .adius o6 ci.cu,a. cu.ve, which ensures safet% of each vehicle and its

occupants and satisfies sight distance re9uirement#

Radius of circular curve, Rdmin



$esign speed, d + **5ph

Rd8in 2 Ma; Rs.$ Rsd

Rsr + dQQQQ !*emax G f s"

where' emax + maximum rate of superelevation+ )#).-)#!' in tropical countr%"

+ )#! in this case Rural in the 4hilippines"

fmax + maximum coefficient of lateral friction

+ )#(* P )#))))!0 P d! 3 )#))/0 P d G )#**"+ )#

+ QQ **! QQQQQQ + *!#8 m,

!*)#! G )#"

Rs. 2 sa "#9 8

Rsd + SS$! J . P m"

$esign of Stopping Sight $istance

B% using e9uation !#, >eometric $esign of Roadwa%s and Roadside 2% E## A5in%emi'

SS$ + )#!*.dt p G vd!J!0f & G >"

where'

d + design speed + ** 5ph

t p + perception time, 2ased on 2ehavior of population + !#) seconds Rural collector road"

f & + coefficient of friction as in 7igure !#(, page !#, >eometric $esign,

with speed + ** 5ph and assuming tires of cars in good condition'

+ )#!> + /1 at maximum condition

SS$ + )#!*. P **P !#) P G **! J !0P)#! G /1"+ .(#)/; sa% .( m

+ >9 8

Rsd + SS$! J . P m"

Fhere' m 2 distance from curve to o2stacle

+ road center lane width G shoulder width G drainage width

+ (#0 G # G #)+ #8)m

+ 8(! J . P #8)"

Rsd 2 "<& 8

Rdmin + :ax *(; 0/

Rd8in 2 "#9 8

Mini8u8 ,en5t+ o6 t.ansition cu.ve

Lsd8in 2 MA LSc LSs

where'

=Sdmin + minimum desira2le length of transition curve

=Sc + length of transition curve to fullfill rate of change of lateral acceleration

/



=Ss + length of transition curve to fullfill rate of introduction of the designed

superelevation re9uirements

=Sc + )#)!! P d d! J Rdmin" 3 !* Pedmax #########e9uation !#(

d + ** #5phRdmin + *( m

edmax + maximum desira2le rate of super elevation

+ :<M emax ; Od! J !.! P Rdmin"N+ :<M )#! ; )#!

+ )#!

then,

=Sc + )#)!! P ** **!J *( " 3 !* P )#!

2 9)< 8

=Ss + edmax P )# P F G Fe J RS # E9uation !#(!

where' edmax + )#!

F + normal pavement width + (#0) mRS + allowa2le relative slope + )# 1

Fe + extra widening at the circular curve + Fd min

+ )#) n#l! J Rdmin G )#) P d J Rdmin")# ##########e9uation !#!/where'

n + num2er of traffic lanes + lanes x ! + ! lanes

l + length of wheel 2ase of the design vehicle

+ (#0)mSu2stituting all values,

Fe + O)#) P ! P (#0! J *( N G O)#) P ** J *("J!N

+ )#/8 m=Ss + )#! P )# (#0 G )#/8 J )#))

+ 08#). m; sa% <?8

Lsd8in 2 MA LSc LSs

+ :ax (!#!0; 08

+ 08 m

Based on t+e avai,a,e p.oect site ,i8itations i)e) .oad passin5 a,on5 ui,t up a.eas$

s8a,, tan5ent ,en5t+s$ s+a.p co.ne.s$ and steep 5.ades$ t+e aove otained va,ues

0it+ a desi5n speed o6 ##4p+ cannot e attained$ +ence$ .educe t+e speed ,i8it to

'%4p+ in o.de. t+at t+e t+.es+o,d va,ues 0i,, 6it t+e avai,a,e space)

• T. Desi5n Speed:

*d 2 '% 4p+


!5ph;i#e# in the range 0!5ph 3(.5ph# &hus, the minimum desira2le speed that

corresponds to the $esign Service flow rate is (.5ph#


?9"; Capacit% C"; 4roportion 7lows of various vehicle t%pes 47m" and $esira2ledesign speed'

?9 + )#8!JΣ{47mJ?maxm"N G ((#/9JC 3 00#/ 9JC!, in this case ?max

+ d + )5ph


(. + )#8! x 50 G ((#/9JC 3 00#/ 9JC!

B% 9uadratic E9uation; 9JC + )#80

*



Idea, /,o0 Rate:

Assuming the capacit% of the lane to 2e !,))pcphpl

Actual capacit% of the lane due to mixed traffic + <deal capacit% x ft

7t, is given 2% the e9uation' JΣ47m" x 4CEm)]

= 1

O )#(J)#08PN G O)#0J)#08P#!N"

2 %)?'

6ence, the actual capacit% is' )#8 x !)) + 88

&herefore the $esign Service 7low Rate, $S7R + )#80 x 88

+ .*pcphpl


$S7R

Su2stituting all values; + /80.*

2 )#8); sa% " ,ane pe. di.ection

One (" ,ane in eac+ di.ection is .e3ui.ed in o.de. to acco88odate t+e p.evai,in5

Desi5n De8and T.a66ic 6,o0 6o. #%1 p.ivate ca.s and ta;icas on,)


Lane @idt+:



where'

F=dmin + minimum desira2le width of vehicle traffic lane

Fv + width of design vehicle; taxica2 + !#) meters

Slm + space re9uired for lateral movements, )#!-)#)m" for speed L+()5ph 2ut

I )5ph

+ )#)mSlf + space re9uired due to fear of sidewal5 or o2ects, )#(-)#)m" for speed

L+()5ph 2ut I)5ph + )#)m


F=dmin + !#) G )#) G )#)

+ 9)"% 8ete.s

ii) Road ca8e.

&%pe of pavement is assumed to 2e Asphalt 2ituminous" Concrete# &hus a cross 3 fall of )'1 is to 2e provided#

iii) D.aina5e



• S+ou,de. 2 ")' 8 ; 2 9)%%

• Mao. ,anes 2 9)" 8 ; 2 &)%

• D.aina5e 2 ")% 8 ; 2 )%%

Tota, Re3ui.ed @idt+ 2 "")% 8ete.s

Gene.a, Desi5n o6 Fo.i7onta, cu.ve

Route A-!-E:

.



Mini8u8 .adius o6 ci.cu,a. cu.ve, which ensures safet% of each vehicle and its

occupants and satisfies sight distance re9uirement#


$esign speed, d + )5ph

Rd8in

2 Ma; Rs.$ Rsd

Rsr + dQQQQ !*emax G f s"

where' emax + maximum rate of superelevation

+ )#).-)#!' in tropical countr%"+ )#! in this case Rural in the 4hilippines"


+ )#(* P )#))))!0 P d! 3 )#))/0 P d G )#**"

+ )#8

+ QQ )! QQQQQQ + /(# m,!*)#! G )#8"

Rs. 2 sa &9)'% 8

Rsd + SS$! J . P m"

$esign of Stopping Sight $istance


SS$ + )#!*.dt p G vd!J!0f & G >"

where'

d + design speed + ) 5pht p + perception time, 2ased on 2ehavior of population

+ !#) seconds Rural collector road"


with speed + ) 5ph and assuming tires of cars in good condition' + )#

> + /1 at maximum condition

SS$ + )#!*. P )P !#) P G )! J !0P)# G /1"

+ 0(#8(; sa% 00 m

+ << 8

Rsd + SS$! J . P m"

Fhere' m 2 distance from curve to o2stacle

+ road center lane width G shoulder width G drainage width+ (# G # G #)

+ #/)m

+ 00! J . P #/)"

Rsd 2 <9)" 8

Rdmin + :ax /(#; 0(#!

Rd8in 2 &9)' 8

C+ec4in5 i6 t+e.e is a need 6o. Spi.a, Cu.ve:

d!J + )!J+ ))mL /(#)m, &hus spirals should 2e provided#


Lsd8in 2 MA LSc LSs

8



where'

=Sdmin + minimum desira2le length of transition curve=Sc + length of transition curve to fullfill rate of change of lateral acceleration



=Sc + )#)!! P d d! J Rdmin" 3 !* Pedmax #########e9uation !#(

d + ) #5ph

Rdmin + /(# m

edmax + maximum desira2le rate of super elevation

+ :<M emax ; Od! J !.! P Rdmin"N+ :<M )#! ; )#0

+ )#!

then,

=Sc + )#)!! P ) )

!

J /(# " 3 !* P )#!2 &)'< 8


where'

edmax + )#!F + normal pavement width + (#) m

RS + allowa2le relative slope + )# 1


+ )#) n#l! J Rdmin G )#) P d J Rdmin")# ##########e9uation !#!/where'

n + num2er of traffic lanes + lanes x ! + ! lanes

l + length of wheel 2ase of the design vehicle+ (#0)m


Fe + O)#) P ! P (#0! J /(# N G O)#) P ) J /(#"J!N+ )#.0 m

=Ss + )#! P )# (# G )#.0 J )#))

+ 0*#!. m; sa% <#)98

Lsd8in 2 MA LSc LSs

+ :ax !/#0; 0*#(

+ 0*#( m

Cu.ve a,on5 Route A-C-E:

9%1 O/ p.ivate ca.s and 9%1 o6 Ta;icas$ Miniuses and Bi5 uses to5et+e. in t+e

t.a66ic st.ea8 a,on5 A-C-E .oute)

T+e.e6o.e:

$$7R private cars + /.( x #) + /.( pcph$$7R 2ig 2uses + 8! x !# + !!.) pcph

$$7R mini2uses + 0/ x # + /.0 pcph

$$7R taxica2s + !*0 x #! + (!8 pcph (8*/ pcph

• Desi5n Speed

*d 2 Min * (t.a66ic * (te..ain )) e3uation )

*d 2 * (t.a66ic

2 )#J47cJc G 47tJt G 47m2Jm2 G4722J22

+ )#J )#)P)#(J.) G )#!)P)#(J*) G )#!)J/) G )#)J)

+ /(#!(, sa% /0 5ph

)



Fo0eve.$ due to t+e avai,a,e site ,i8itations i)e) .oad passin5 a,on5 ui,t up a.eas$

s8a,, tan5ent ,en5t+s$ s+a.p co.ne.s and steep 5.ades$ t+e desi5n speed o6 &<4p+

cannot e attained) Fence$ adopt a speed ,i8it o6 <%4p+ in o.de. t+at t+e t+.es+o,d

va,ues 0i,, 6it t+e avai,a,e space)

6ence, for a level of service C, the desira2le speed range is' ?max + .5ph to ?max +!5ph;i#e# in the range (!5ph 3 !.5ph# &hus, the minimum desira2le speed that

corresponds to the $esign Service flow rate is !.5ph#


?9"; Capacit% C"; 4roportion 7lows of various vehicle t%pes 47m" and $esira2le

design speed'

?9 + )#8!JΣ{47mJ?maxm"N G ((#/9JC 3 00#/ 9JC!, in this case ?max +

d + 0)5ph


!. + )#8! x 40 G ((#/9JC 3 00#/ 9JC!

B% 9uadratic E9uation; 9JC + )#8/

Idea, /,o0 Rate:


Actual Capacit% of the lane due to mixed traffic + <deal capacit% x f t

f t is given 2% e9uation' JΣ47m" x 4CEm"

f t + J)# x #) G )#)/ x #! G )#! x # G )# x !#

+ #(6ence the actual capacit% is' #( x !)) + !*()pcph

&herefore the $esign Service 7low Rate; DS/R 2 %)?& ; #9% 2 <"pcp+p,)


$S7R

Su2stituting all values; + (8*/

!0!

2 #/; sa% ,anes pe. di.ection

T0o ( ,anes in eac+ di.ection a.e .e3ui.ed in o.de. to acco88odate t+e p.evai,in5

Desi5n De8and T.a66ic 6,o0)


&%pe of

vehicle

4roportion

in traffic

Sort

&otal proportion

Cum#4roportion

Fidthm"

4rivatecar

)# !81 !81 !

&axica2s )#)/ !1 01 !#

:ini2us )#!) (81 .)1 !#(

Big 2us )#) !)1 ))1 !#/

$esign ehicle width 2ased on .th percentile + !#(* m

Lane @idt+:

i)Mini8u8 @idt+ o6 a T.a66ic Lane

'




where'F=d

min + minimum desira2le width of vehicle traffic lane, in this proect, mini-2us

Fv + width of design vehicle on . th percentile

+ !#(* metersSlm + space re9uired for lateral movements, )#-)#()m" for speed L+()5ph

2ut I)5ph

+ )#()mSlf + space re9uired due to fear of sidewal5 or o2ects, )#!-)#0)m" for speed

L+()5ph 2ut I )5ph

+ )#0)m


F=d

min

+ !#(* G )#()G )#0)+ (#)* meters; sa 9)"%8

ii) P.ovide a 8edian o6 ")% 8 0ide)

iii) Road ca8e.

&%pe of pavement is assumed to 2e Asphalt 2ituminous" Concrete# &hus a cross 3

fall of )'1 is to 2e provided#

iv) D.aina5e



• Side 0a,4 2 ")' 8 ; 2 9)%%

• < Mao. ,anes 2 9)" 8 ; < 2 ")<%

• D.aina5e 2 ")% 8 ; 2 )%%

• Median 2 ")% 8 ; " 2 ")%%

Tota, Re3ui.ed @idt+ 2 ">)<%8ete.s

Fo0eve.$ t+e avai,a,e c,ea. distance et0een ui,din5 ,ine 6.o8 A-C is on,

app.o;i8ate, "" 8ete.s$ +ence usin5 t+is Route 6o. t+e .e8ainin5 t.a66ic 6,o0 is not

app,ica,e$ in t+is case adopt .oute A-!-E 6o. a,, t+e t.a66ic 6,o0s) A,so$ t+e ,en5t+ o6

t+e ,oc4 is a.ound '% 8ete.s$ t+us$ t+e distance 6.o8 C-A is not too 6a. 6o.passen5e.s to ta4e t+e pu,ic t.anspo.t at A) E;istin5 Route 6.o8 A-B-C-D 0i,, e

8aintained and 0i,, se.ve as an access o. dist.iuto. .oad)

Desi5n Route A-!-E 6o. a,, Tpes o6 *e+ic,es:

Dete.8ination o6 Nu8e. o6 ,anes to cate. 6o. a,, Tpes o6 ve+ic,es to5et+e. in t+e

t.a66ic st.ea8 a,on5 A-!-E .oute)

T+e.e6o.e:

DD/R:

i) p.ivate ca.s$$7R car" + 0..). x )#! x )# x )#(

)#8

2 "&&< ca.s=+ou.

ii) Ta;icas

$$7R taxica2s 2 0..). x )#! x )#!) x )#(

)#8

2 &'< ta;icas=+ou.

iii) Bi5 Buses

$$7R 2ig 2uses" + 0..). x )#! x )#) x )#(

)#8 + 9"%i5 uses=+ou.

!



iv) Mini Buses

47 m" + )#!)

$$7R mini 2uses" + 0..). x )#! x )#!) x )#(

)#8 + &" 8iniuses=+ou.

$$7R private cars + //0 x #) + .!* pcph

$$7R 2ig 2uses + () x !# + () pcph

$$7R mini2uses + /! x # + 8(! pcph

$$7R taxica2s + /0 x #! + *. pcph (.0 pcph

• Desi5n Speed

Adopt t+e speed ,i8it o6 <% 4p+


!5ph;i#e# in the range (!5ph 3 !.5ph# &hus, the minimum desira2le speed that

corresponds to the $esign Service flow rate is !.5ph#


?9"; Capacit% C"; 4roportion 7lows of various vehicle t%pes 47m" and $esira2le

design speed'

?9 + )#8!JΣ{47mJ?maxm"N G ((#/9JC 3 00#/ 9JC!

, in this case ?max+ d + 0)5ph


!. + )#8! x 40 G ((#/9JC 3 00#/ 9JC!

B% 9uadratic E9uation; 9JC + )#8/

Idea, /,o0 Rate:


Actual Capacit% of the lane due to mixed traffic + <deal capacit% x f t

f t is given 2% e9uation' JΣ47m" x 4CEm"

f t + J)# x #) G )#! x #! G )#! x # G )# x !#+ )#*.

6ence the actual capacit% is' )#*. x !)) + /(. pcph

&herefore the $esign Service 7low Rate; DS/R 2 %)?& ; "&9> 2 "'# pcp+p,)

Nu8e. o6 ,anes: 2 $$7R $S7R

Su2stituting all values; + (.0

*!

2 !#0; sa% 9 ,anes pe. di.ection

T+.ee (9 ,anes in eac+ di.ection a.e .e3ui.ed in o.de. to acco88odate t+e p.evai,in5

Desi5n De8and T.a66ic 6,o0)

Desi5n C.oss SectionCu.ve at !:

(



&%pe of vehicle

4roportionin traffic

Sort

&otal

proportion

Cum#

4roportion

Fidth

m"

4rivate

car

)#) )1 )1 !

&axica2s )#!) !)1 *)1 !#

:ini2us )#!) !)1 8)1 !#(

Big 2us )#) )1 ))1 !#/

$esign ehicle width 2ased on .th percentile + !#! m

Lane @idt+:


'F=d

min + Fv G Slm G Sf

where'

F=dmin + minimum desira2le width of vehicle traffic lane, in this proect, mini-2us

Fv + width of design vehicle on . th percentile

+ !#! meters

Slm + space re9uired for lateral movements, )#-)#()m" for speed L+()5ph 2ut I)5ph

+ )#()m

Slf + space re9uired due to fear of sidewal5 or o2ects, )#!-)#0)m" for speedL+()5ph 2ut I )5ph

+ )#0)m


F=dmin + !#! G )#()G )#0)

+ !#8 meters; sa 9)%8

Adopt ,ane 0idt+ o6 9)%%8 6o. t+e oute. and inne. ,anes

ii) P.ovide a 8edian o6 %)&% 8 6o. sa6et pu.poses to p.event ve+ic,es to c.ossove.

t.a66ic and as a p+sica, sepa.ation et0een t0o ( di.ectiona, 6,o0)

(/o. t+e 8ini8u8 0idt+ 2 ")%8$ adopt %)&%8 due to space ,i8itations and site

conditions)

iii) Road ca8e.

&%pe of pavement is assumed to 2e Asphalt 2ituminous" Concrete# &hus a cross 3 fall of )'1 is to 2e provided#

iv) D.aina5e


Based on actual experience, $rainage is necessar% considering that the terrain is rolling#

&his will prevent earl% damage to road during heav% downpour of rain water#

v) Const.uct conc.ete a..ie.s a,on5 steep sides,opes)

vi) P.ovide us as a,on5 ui,t up a.eas 6o. d.oppin5 and co,,ectin5 passen5e.s


• Side 0a,4 2 ")' 8 ; 2 9)%%

• & Mao. ,anes 2 9)% 8 ; & 2 ">)%%

• D.aina5e 2 ")% 8 ; 2 )%%

• Median 2 %)& 8 ; " 2 %)&%

Tota, Re3ui.ed @idt+ 2 9)&%8ete.s

Gene.a, Desi5n o6 Fo.i7onta, cu.ves

• Esta,is+in5 t+.es+o,d va,ues:

0



:inimum radius of circular curve, which ensures safet% of each vehicle and its occupants

and satisfies sight distance re9uirement#


$esign speed, d + 0)5ph

Rdmin + :ax Rsr, Rsd

Rsr + dQQQQ

!*emax G f s"

where' emax + maximum rate of superelevation+ )#).-)#!' in tropical countr%"

+ )#! in this case Rural in the 4hilippines"


+ )#(* P )#))))!0 P d

!

3 )#))/0 P d G )#**"+ )#!)

+ QQ 0)! QQQQQQ + *#!* m,

!*)#!G )#!"

Rs. 2 sa '>

Rsd + SS$! J . P m"

Desi5n o6 Stoppin5 Si5+t Distance


SS$ + )#!*.dt p G vd!J!0f & G >"

where'

d + design speed + 0) 5ph

t p + perception time, 2ased on 2ehavior of population, the expected .th

4ercentile + !#) seconds Rural collector road"


with speed + 0) 5ph and assuming tires of truc5s in goodcondition'

+ )#(0

> + /1 at maximum condition

SS$ + )#!*. P 0) P !#) P G 0)! J !0P)#(0 G /1"

+ (*#88; sa% 0) m

+ <% 8

Rsd + SS$! J . P m"

Fhere' m 2 distance from curve to o2stacle+ road center lane G side wal5 G drainage

+ 0# G # G #)

+ *#)m

+ 0)! J . P *#)"

Rsd + !.#*; sa% !8

Rdmin +:ax .; !8

Rd8in 2'> 8

C+ec4in5 i6 t+e.e is a need 6o. Spi.a, Cu.ve:



d!J + 0)!J+ (!)mL .m, &hus spirals should 2e provided#


Lsd8in

2 MA LSc LSs

where'

=Sdmin + minimum desira2le length of transition curve=Sc + length of transition curve to fullfill rate of change of lateral acceleration



=Sc + )#)!! P d( J Rdmin more critical" #########e9uation !#()

d + 0) 5ph

Rdmin + . m

ed

max

+ maximum desira2le rate of super elevation+ :<M emax ; Od! J !.! P Rdmin"N

+ :<M )#! ; )#0+ )#!

then,

=Sc + )#)!! P 0)(J .

2 <)9% 8


where'edmax + )#!

F + normal pavement width + (#) m

RS + allowa2le relative slope + ! 1Fe + extra widening at the circular curve + Fd min

+ )#) n#l! J Rdmin G )#) P d J Rdmin")# ##########e9uation !#!/

where'n + num2er of traffic lanes + ( lanes x ! + / lanes


+ /#) m

Su2stituting all values,Fe + O)#) P / P /#! J / N G O)#) P 0) J /"J!N

+ !#.!m

=Ss + )#! P )# (#) G !#.! J )#)!+ *#0/ m; sa% "#)'%8

Lsd8in 2 MA LSc LSs

+ :ax !0#!*; *#)

2 <)# 8

Mini8u8 C.itica, ,en5t+ o6 Tan5ent

CTL 2 MA "% Rd8in %)' *d ) ) ) ) ) ))e9uation !#0*+ :A ) P / )# ; ! P 0)

+ :A *0#.( ; .)

2 >% 8

Desi5n Ca,cu,ation o6 Fo.i7onta, A,i5n8ent

#Selection of horiHontal curve t%pe

?sing'

Rdmin + / md + 0)5ph

=sdmin + !0#!* m

Angle delta + 0 degrees

/



Solve for angle teta + .) P =sdmin J π P Rdmin # # # # # # #e9uation !#(

+ !0#.( degrees I )#) P 0 ; therefore com2ination of

circular and transition curve is re9uired!# $etermine the circular curve and transition curves

$esign Criteria'Angle delta + 0 degrees

Rdmin + / m

=sdmin + !0#!* m

?nit spiral method'

lu + =SJ ! P Rd P =S")#

+ !0#!* J ! P / P !0#!*")#

+ )#0/; sa% )#0*

2% using ta2le page !#(8-!#0);

lu + )#0*xu + )#0/**

%u + )#)(00

xs + xu P ! P R P =s")# + !0#(. m # # # # # # # # #e9uation !#(/

%s + %u P ! P R P =s")# + #.) m # # # # # # # # # e9uation !#(*

5 + xs 3 Rsin teta

+ !0#(. 3 /sin!0#.(degrees

+ )#./ m& T + R P tan deltaJ!"

+ / P tan 0J! degrees + !.#( mRc + R 3 =s! J !0 P R"

+ #/ m

=cu + Rc P delta - !Pteta" P π J .)

+ 0#!) m

Since t+e Len5t+ o6 Spi.a, cu.ve (Lsd8in 2 <)# 8 is 8uc+ ,ess t+an t+e Len5t+ o6

Cu.ve (Lcu 2 <)% 8 Adopt Rd8in 2 >% 8 in o.de. to 6it t+e cu.ve and 6o. suita,e

desi5n)

So,ve 6o. t+e ne0 Mini8u8 ,en5t+ o6 t.ansition cu.ve

Lsd8in 2 MA LSc LSs

where'


=Sc + length of transition curve to fullfill rate of change of lateral acceleration=Ss + length of transition curve to fullfill rate of introduction of the designed


=Sc + )#)!! P d( J Rdmin use this; more critical" #########e9uation !#()

d + 0) 5ph

Rdmin + .) m

then,=Sc + )#)!! P 0)(J .)

2 "#)&% 8


where'


RS + allowa2le relative slope + ! 1


+ )#) n#l! J Rdmin G )#) P d J Rdmin")# ##########e9uation !#!/

where'n + num2er of traffic lanes + ( lanes x ! + / lanes

*




+ ! ft# + *#/! m

Su2stituting all values,Solve for the Extra widening of the circular curve;

Fe + O)#) P / P *#/!! J .) N G O)#) P 0) J .)"J!N

+ !#/m=Ss + )#! P )# (#) G !#/ J )#)!

+ /#8 m; sa% "#)%8

Lsd8in 2 MA LSc LSs

+ :ax *#/); *#)

2 "#)&% 8


#Selection of horiHontal curve t%pe

?sing'Rdmin + .) m

d + 0)5ph

=sdmin + *#/) mAngle of deflection + 0 degrees


+ !#/) degrees I )#) P 0 ; therefore com2ination of

circular and transition curve is re9uired(# $etermine the coordinates of the center of the circular curve and transition curves

$esign Criteria'Angle delta + 0 degrees

Rdmin + .) m

=sdmin + *#/) mSolve for the e9uivalent length of a unit curve'

lu + =SJ ! P Rd P =S")#

+ *#/) J ! P .) P *#/)")#

+ )#(( 2% using ta2le page !#(8-!#0);

lu + )#((xu + )#(!8/

%u + )#)8

xs + xu P ! P R P =s")# + *#08 m # # # # # # # # #e9uation !#(/

%s + %u P ! P R P =s")# + )#/( m # # # # # # # # # e9uation !#(*

5 + xs 3 Rsin teta + *#08 3 .)sin!#/)degrees

+ )#)0 m

& T + R P tan deltaJ!" + .) P tan 0J! degrees

+ 0)#*/ m

Rc + R 3 =s! J !0 P R" + *8#.( m


+ 0)#( m

T+e.e6o.e at Cu.ve !:

?se ' R dmin + .) m

=sd + *#/) m

Rc + *8#.( m

=cu + 0)#( m

$elta + 0#)) degrees&eta + !#/) degrees

.



&U + 0)#*/ m

K + )#)0 m

d + 0) 5ph

At Cu.ve app.oac+in5 Point D


Lsd8in 2 MA LSc LSs

where'


=Sc + length of transition curve to fullfill rate of change of lateral acceleration

=Ss + length of transition curve to fullfill rate of introduction of the designedsuperelevation re9uirements

=Sc + )#)!! P d( J Rdmin more critical" #########e9uation !#()

d + 0) 5phRdmin + 8) m

then,

=Sc + )#)!! P 0)(J 8)

2 "')&' 8


where'


RS + allowa2le relative slope + ! 1 for 0-/ lanes"

Fe + extra widening at the circular curve + Fd min+ )#) n#l! J Rdmin G )#) P d J Rdmin")# ##########e9uation !#!/

where'

n + num2er of traffic lanes + ( lanes x ! + / lanesl + length of wheel 2ase of the design vehicle

+ *#/! m


Fe + O)#) P / P *#/!! J 8) N G O)#) P 0) J 8)"J!N+ !#(. m

=Ss + )#! P )# (#) G !#(. J )#)!

2 "&)"< 8

Lsd8in 2 MA LSc LSs

+ :ax #/; /#0

2 "&)"< 8

$esign Criteria'

Angle delta + /) degrees

Rdmin + 8) m=sdmin + /#0 m


+ )#!. degrees I )#) P /) ; therefore com2ination ofcircular and transition curve is re9uired

Solve for the e9uivalent length of a unit curve'

lu + =SJ ! P Rd P =S")#

+ /#0 J ! P 8) P /#0")#

+ )#!88; sa% )#()

2% using ta2le page !#(8-!#0);

lu + )#()

xu + )#!88*%u + )#)).8

xs + xu P ! P R P =s")# + /# m # # # # # # # # #e9uation !#(/

8



%s + %u P ! P R P =s")# + )#0. m # # # # # # # # # e9uation !#(*

5 + xs 3 Rsin teta + /# 3 8)sin)#!.degrees

+ )#) m

& T + R P tan deltaJ!" + 8) P tan /)J! degrees

+ #8/ m

Rc + R 3 =s! J !0 P R" + .8#.. m


+ /#.* m

?se ' R dmin + 8) m

=sd + /#0 m

Rc + .8#.. m

=cu + /#.* m$elta + /)#)) degrees

&eta + )#!. degrees&U + #8/ m

K + )#) m

d + 0) 5ph

B.ea4do0n:

Station ) G ))) starts at point V

/o. t+e /i.st Cu.ve at !:

Station &S + ) G )/0#.

Station SC + ) G ).!#0Station 4< + ) G )#/Station CS + ) G !!#.

Station S& + ) G 0)#.

/o. t+e Second Cu.ve app.oac+in5 Point D

Station &S + ) G !#!

Station SC + ) G /.#!/

Station 4< + ) G !)0#.Station CS + ) G !()#(

Station S& + ) G !0/#!*

C+ec4 6o. t+e Fo.i7onta, Len5t+ et0een t0o cu.ves (TL "-

+ Station S& for the 7irst Curve 3 Station &S of the Second Curve+ !#! 3 0)#.

2 "")?<' 8

So,ve 6o. Mini8u8 C.itica, ,en5t+ o6 Tan5ent (CTL

C&= + :A ) Rdmin )# ; !d # # # # # ##e9uation !#0)

+ :A ) P 8) )# ; ! P 0)+ :A 8 ; .)

2 ?' 8 H "")?<' Since CTL H TL "-$ a Co8pound Cu.ve 8ust e

used to .ep,ace t+e Cu.ves " and )

Redesi5n t+e Cu.ve at Point !:

$esign Criteria'

Angle delta + 0 degrees

Rdmin + .) m

So,ve 6o. t+e Len5t+ o6 cu.ve

!)



=cu + !P π P R P delta

(/)+ *(#0) m

So,vin5 6o. t+e tan5ent ,ine:

& + R tan deltaJ!

+ 0)#*/ m

se : R dmin + .) m

=cu + *(#0) m

$elta + 0#)) degrees& + 0)#*) m

d + 0) 5ph

Redesi5n t+e Cu.ve App.oac+in5 Point D:

$esign Criteria'Angle delta + / degrees

Rdmin + 8) m

So,ve 6o. t+e Len5t+ o6 cu.ve

=cu + !P π P R P delta

(/)

+ )!#) m

So,vin5 6o. t+e tan5ent ,ine:

& + R tan deltaJ!

+ *#(0 m

se : R dmin + 8) m

=cu + )!#) m

$elta + /#)) degrees

& + *#(0 md + 0) 5ph

T+e.e6o.e:

/o. est /it o6 t+e cu.ves on t+e p,an ,aout:

Station % J %%% sta.ts at point K

/o. t+e /i.st Cu.ve at !:

Station 4& + ) G )/0#.

Station 4< + ) G )#Station 4C + ) G (.#!

/o. t+e Second Cu.ve app.oac+in5 Point DStation 4& + ) G (.#!

Station 4< + ) G 8#8

Station CS + ) G !0)#(

Tas4 9

Desi5n o6 *e.tica, Cu.ves

Ca,cu,ation o6 T+.es+o,d *a,ues o6 *e.tica, Tan5ent Desi5n Pa.a8ete.

!



> + -(#(( 1

> + -/#/ 1

> + -#0 1

Note:

&he design of the grade was 2ased on site condition, i#e# the steep grades and thesideslopes# Based on experience, it is advisa2le to cut the gradeline to suit the site

conditions, considering that the terrain is rolling# Concrete 2arriers will 2e provided along

edge of the road with critical sideslopes#

6orsepower + !.)

Feight of Bus + 0),)))

Assu8e:

A + B P 6 + ! m!

Engine Efficienc% + )#.!

α + Air Resistance Coefficient + )#)))/

+ 0) 5ph + # mps

! + () 5ph + .#(( mps

f R + )#)).

4f + !*) P 8#. P 64 P Engine Efficienc% (#/ P

+ !*) P 8#. P !.) P )#.!

(#/ P # + ,8)

Fgt# P f R + Feight P f R

+ 0),))) P 8#. P )#)).

+ (,(/ Mewton

Rair + α P A d!

+ )#)))/ P ! P 0)!

+ #8! Mewton

At 4oint K'Rf + Rair G Fgt# P >max"J)) G Fgt P f

+ #8! G 0),))) P )#)/ P 8#." G 0),))) P )#)). P 8#." 8#.

+ !(,.0!

4f 3 Rf+ Fgt P a P 8#."J 8#.

+ 0),))) P a P 8#." J 8#.

,8) 3 !(,.0! + 0),))) P a P 8#." J 8#.

a + - )#!! mps!

!! +

! 3 !P a P =g

=g + ! 3 !

!

!P a

+ #"! 3 .#(("!

! P )#!!"+ !!#.( m

!!



!! +

! 3 !P a P =g

.#((! + #! 3 ! P a P !!#.( a + )#!! mps!

Rf + Rair G Fgt# P >max"J)) G Fgt P f

where'

4f 3 Rf + Fgt P a P 8#." J 8#.

Rf + 4f G Fgt P a

+ ,8) G 0)))) P )#!!

+ !(,88)

!(,88) + #8! G 0),))) P >max P 8#." G 0),))) P )#)). P 8#."

>max + #(! 1

7rom calculation a2ove, < conclude that with length + !!#.( m, the maximum

appropriate gradient is #(! 1, since design maximum grade used is /#/ 1 not too farfrom the computed >max, hence adopt design grades#

Ma;i8u8 and Mini8u8 Len5t+ o6 a s88et.ica, Sa5 *e.tica, Cu.ve at Point

App.oac+in5 Point D)

SL*d8in 2 MA Lnv Lc La

where'

S=dmin + minimum desira2le length of sag vertical curve

=nv + SS$! P #// J ))P!h G !PSS$Ptan alpha"# # # # # # # ##e9uation !#(where'

SS$ + 0) m

A + -/#/ 1 - -#01"" + #/ 1h + height of headlight a2ove the surfaceassumed to 2e + )#/)m"

alpha + 2eam angle assumed to 2e + degree"

d + 0) 5ph

=nv + 0)! P #/ J ))P!P)#/ G !P0)Ptan)"

+ *# m

=c + d! P A J (.8 #

+ 0#** m

=a + ! d

+ .) m

S=dmin + :A *# ; 0#** ; .)

2 >% 8

Point D:

7or the sag curve

S=min + .) m> + -/#/ 1

>! + -#0 1

Ma;i8u8 and Mini8u8 Len5t+ o6 a s88et.ica, C.est *e.tica, Cu.ve at Point

App.oac+in5 Point E)

C*Ld8in 2 MA Lsd Lc La

where'

C=dmin + minimum desira2le length of crest vertical curve

!(



=sd + SS$! P #// J !))Pa G G 2 G !a )# P 2 )## # # # # # # ##e9uation !#0.

where'SS$ + 0) m

A + -(#(( 1 - -/#/1"" + (#!. 1

a + e%e height a2ove the road surfaceassumed to 2e + #)m" 2 + o2ect height a2ove the road surfaceassumed to 2e + )#"

=nv + 0)! P (#!. J !))P#) G G )#) G !#)") P )# )#"+ .# m

=c + d! P A J (.8 #

+ (#) m

=a + ! d

+ .) m

S=d

min

+ :A (#) ; .# ; .)2 >% 8

Point D:

7or the crest curve

S=min + .) m> + -(#(( 1

>! + -/#/ 1

Desi5n o6 Passin5 o. Ove.ta4in5 Si5+t Distance

B% using 7igure !#( AAS6&US $erivation of 4assing $istance, page !#), >eometric$esign 2% E##A5in%emi'

7or a design speed d + 0) 5ph

&he element of passing sight distance is 0)-/!ft#; 4S$ + (*-8)meters"But, E9uation !#* page !# gives 4S$L+ /d, + / P 0) + !0)m

&herefore'

PSD 2 <%8 (6o. conse.vative desi5n

Based on t+e site conditions$ Ove.ta4in5 is not possi,e conside.in5 t+at t+e ,en5t+

o6 t+e .oad is too s+o.t and is situated a,on5 ui,t up a.eas)

geometric design.doc

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