International Journal of Civil Engineering and Technology (IJCIET)
Volume 10, Issue 04, April 2019, pp. 1808–1821, Article ID: IJCIET_10_04_189
Available online at http://www.iaeme.com/ijmet/issues.asp?JType=IJCIET&VType=10&IType=4
ISSN Print: 0976-6308 and ISSN Online: 0976-6316
© IAEME Publication
Scopus Indexed
EVALUATION AND IMPROVEMENT OF RAMP
JUNCTIONS ON MULTILANE URBAN
ARTERIAL STREETS
Majed Msallam
Associate Professor, Civil Engineering, Al- Balqa' Applied University, Faculty of
Engineering Technology (FET), Department of Civil Engineering, Amman-Jordan
Basim Jrew
Professor, Civil Engineering, Isra University, Amman-Jordan
Raed Nazzal Al-Muhanna
Assistant Professor, Civil Engineering, Isra University, Amman-Jordan
Mohammed Jabbar Hussein
MSc. in Engineering Project Management, Isra University, Amman-Jordan
ABSTRACT
Ramp-freeway junctions are almost designed to allow high-speed and high
capacity merging and diverging with the minimum disruption to the adjacent traffic.
One source of conflict on freeway weaving section, when the merge and diverge is
short require vehicle to entering or exiting the freeway to execute it need one or more
lane changes. The operational analysis of weaving, merging and diverging of rampjunction in freeway are applicable at multilane highway. The objective of study is to
evaluate and improve the existing ramp and ramp junction in urban area. The study
conducted in Amman-Jordan for major known cloverleaf interchange. Two types of
analysis are conducted, weaving and ramp-junction analysis using highway capacity
manual of 2010 (HCM-2010) methodologies. The highway capacity software program
(HCS-2010) is applied for analysis and improvement of the selected cloverleaf
interchange as a case study. The result of the analysis for the existing condition shows
that the interchange is operating at LOS F for the weaving area. The improvement
results of short-term and medium-term for the weaving area, merging and diverging of
the ramp-junction for the selectedinterchange will be operated at LOS D or LOS C.
Key words: Freeway facilities, Multi-lane highway, Ramp and ramp-junction,
Weaving area, Merging and diverging area, HCM-2010 methodology, HCS-2010
software.
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Evaluation and Improvement of Ramp Junctions on Multilane Urban Arterial Streets
Cite this Article: Majed Msallam, Basim Jrew, Raed Nazzal Al-Muhanna,
Mohammed Jabbar Hussein, Evaluation and Improvement of Ramp Junctions on
Multilane Urban Arterial Streets, International Journal of Civil Engineering and
Technology 10(4), 2019, pp. 1808–1821.
http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=10&IType=4
1. INTRODUCTION
The most resource of interruption on multilane highway is the weaving segment in merge or
diverge ramps. The driver's decision to enter or exit to highway requires one lane change or
more. Such maneuvers effect on the quality of highway facilities and cause high delay, speed
reduction and stops, fuel consumption as well as traffic accidents. Highway capacity manual 2010 (HCM-2010) define ramp as a length of roadway connected two freeway facilities or a
freeway and an arterial street. Entrance and exit maneuvers take place via ramps that designed
to facilitate smooth merging of on ramp vehicles into the freeway traffic stream and smooth
diverging of off-ramp vehicles from the freeway traffic stream to the ramp.
A ramp may contain of up to three geometric elements of freeway or multilane highway
facilities: Ramp-freeway junction, Ramp roadway and Ramp-street junction. The rampfreeway junction almost designed to license high-speed and high capacity merging and
diverging with the minimum disruption to the adjacent traffic when a ramp connects one
arterial to another. The ramp consists of two ramp-freeway junctions and the ramp roadway.
In addition, a ramp-street junction, when a ramp connected to a surface facility such as a
multilane highway, is designed for high speed merging or diverging without control, and it
may be classified as a ramp-freeway junction for the purpose of analysis (HCM- 2010).
Generally, multilane highways have a posted speed limit between 40 and 55 mi/h (60-90
km/h). They have four or six lanes, usually with physical medians or Two-Way LeftTurn
Lanes (TWLTL), and they may also be undivided. The traffic volumes generally differ from
15,000 to 40,000 vehicles per day. It may also go up to 100,000 vehicles per day with grade
separations and no cross-media access offered. According to HCM- 2010, the operational
analysis of weaving, merging and diverging of ramp-junction in freeway are applicable at
multilane highway.
A significant operation characteristic of any transportation facility on the multi-lane
highways is the concept of capacity. Capacity could be defined as the maximum sustainable
flow rate at which vehicles or persons moderately can be predicted to traverse a point or
uniform segment of a lane or roadway through a specified time period under a given roadway,
traffic and environmental as well as control conditions; usually expressed as vehicles per
hour, passenger cars per hour or persons per hour (HCM, 2010).
Cloverleaf interchanges are four-leg interchanges that employ loop ramps to
accommodate left-turning movements. Interchanges with loops in all four quadrants were
referred to as "Full Cloverleaf/s" and all others were referred to as “Partial Cloverleaf/s”. A
partial cloverleaf may be preferred at major-minor crossings, where with the provision of only
two loops, freedom of movement for traffic on the major road can be maintained by
confining the direct at-grade left turns to the minor road. The principal disadvantages of the
cloverleaf are the additional travel distance for left-turning traffic, the weaving maneuver
generated, very short weaving length typically available and the relatively large right-of-way
areas needed. When Collector-Distributor roads "C-D roads" are not used, further
disadvantages include: weaving on the main line, the double exit on the main lanes and
difficulties in placing signing for the second exit. Because cloverleaf are considerably more
expansive than diamond interchanges, they are less common in urban areas and are better
adapted to suburban or rural areas where space is available (AASHTO, 2011).
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Majed Msallam, Basim Jrew, Raed Nazzal Al-Muhanna, Mohammed Jabbar Hussein
2. STUDY AREA
The selected interchange exists on one of the main multi-lane highways in Jordan. Al-Medina
AL-Monawra cloverleaf interchange is located in the Jordanian capital, Amman, connecting
several districts in West Amman, starting from the intersection of the main street Queen Rania
St. near the University of Jordan. It is also considered as the most favorite areas for living due
to its lovely location between the Mediterranean, western, and downtown of Amman (the
center of the city). However, traffic jams are often observed many periods of time during the
day especially at the peak hours periods.
Figure 1 shows the Google earth photography of this cloverleaf interchange.
Figure 1 Al-MadinaAl-Monawra Cloverleaf Interchange. (source: google earth).
3. DATA COLLECTION
The collected data in this study were divided into three types: Geometric data of the ramp
element, vehicles speed along multilane weaving segment and traffic volume through the
ramp total segment data.
All the traffic data was collected from the official and governmental sectors records such
as Greater Amman Municipality "GAM" and the Ministry of Public Works and Housing
(MPWH). The multi-lane highways in this study are classified as urban arterial multilane
highways. While the urban area fall within the responsibility of the Greater Amman
Municipality (GAM), Traffic Department in the ministry of public works and housing was
contacted several times to get the yearly growth of traffic volume in Jordan highways. The
collected data of traffic volumes in the past years shows that the number of vehicles increase
with a growth rate (G) of 6.57% yearly. In addition, field investigation of the study area was
conducted several times daily in order to get the geometric and traffic data for each ramp of
the case study, and any needed data for the analysis. For any data that was too difficult to be
collected; the ideal condition or the default values were used as recommended by highway
capacity manuals (HCM) such as driver population factor (fp) and peak hour factor (PHF).
In order to define the LOS for each ramp, the demand volume under base conditions (V)
for the selected ramp and ramp junction must be estimated and converted to the demand flow
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Evaluation and Improvement of Ramp Junctions on Multilane Urban Arterial Streets
rate under equivalent base conditions (vp). The maximum peak hour volume (PHV) for each
ramp has to be obtained from traffic counters of Greater Amman Municipality (GAM) and
manual count by researchers which distributed in each street. The geometric data and volume
input data in the case study for weaving, merging and diverging in each direction were
determined as shown in Table 1.
The existing data in this table needs to be converted for the future analysis according to
growth rate (6.57%). Therefore, the forecasted values were estimated for short term period of
the next 5 years (i.e; year 2020), and for medium term period of the next 10 years (i.e;
year2025) as shown in the tables 2 and 3 respectively.
The studied interchange have four Ramp-junctions (merge and diverge), Freeway merge
and diverge segments occur primarily at on-ramp and off-ramp junctions with the freeway
mainlane. The required data of ramp-freeway were tabulated as shown in tables 1, 2, 3, 4, 5
and 6.
Table 1 Traffic and geometric data of weaving area for Al-Madina Al-MonawraCloverleaf
Interchange: The Existing condition (2015).
Right Side (West Bound "WB")
Posted
PHV
Lane Width ft
Direction
HV %
speed mi/h
veh/h
(m)
(km/h)
F-F*
3117
2
45 (70)
12 (3.6 m )
R-R*
25
0
45 (70)
12 (3.6 m )
F-R*
2765
2
45 (70)
12 (3.6 m )
R-F*
465
1
45 (70)
12 (3.6 m )
Left Side (East Bound "EB")
Weaving length Posted
PHV
Lane Width ft
Direction
Ls
HV %
speed mi/h
veh/h
(m)
ft (m)
(km/h)
F-F*
480 (145 m)
3150
1
45 (70)
12 (3.6 m )
R-R*
480 (145 m)
20
0
45 (70)
12 (3.6 m )
F-R*
480 (145 m)
575
0
45 (70)
12 (3.6 m )
R-F*
480 (145 m)
1083
1
45 (70)
12 (3.6 m )
*F-F: Freeway-Freeeway, R-R: Ramp-Ramp, F-R: Freeway-Ramp and R-F:Ramp-Freeway.
Weaving lengthLs
ft (m)
460 (140 m)
460 (140 m)
460 (140 m)
460 (140 m)
NO. of
lanes
3
2
2
2
NO. of
lanes
3
2
2
2
Table ‎2 Traffic and geometric data of weaving area for Al-Madeena Al-Monawrainterchange : Shortterm (after 5 years - 2020).
Right Side (West Bound "WB")
Posted
Weaving lengthPHV
Lane Width
NO. of
Direction
HV % speed mi/h
Lsft (m)
veh/h
ft (m)
lanes
(km/h)
F-F*
460 (140 m)
4285
3
45 (70)
12 (3.6 m )
3
R-R*
460 (140 m)
34
0
45 (70)
12 (3.6 m )
2
F-R*
460 (140 m)
3801
3
45 (70)
12 (3.6 m )
2
R-F*
460 (140 m)
639
2
45 (70)
12 (3.6 m )
2
Left Side (East Bound "EB")
Weaving length
Posted
PHV
Lane Width
NO. of
Direction
Ls
HV % speed mi/h
veh/h
ft (m)
lanes
ft (m)
(km/h)
F-F*
480 (145 m)
4330
2
45 (70)
12 (3.6 m )
3
R-R*
480 (145 m)
27
0
45 (70)
12 (3.6 m )
2
F-R*
480 (145 m)
790
0
45 (70)
12 (3.6 m )
2
R-F*
480 (145 m)
1489
2
45 (70)
12 (3.6 m )
2
*F-F: Freeway-Freeeway, R-R: Ramp-Ramp, F-R: Freeway-Ramp and R-F:Ramp-Freeway.
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Majed Msallam, Basim Jrew, Raed Nazzal Al-Muhanna, Mohammed Jabbar Hussein
Table Error! No text of specified style in document. Traffic and geometric data of weaving area for
Al-MadeenaAlMonawra interchange : Mid -term (after 10 years - 2025).
Right Side (West Bound "WB")
Posted
PHV
Lane Width
Direction
HV %
speed mi/h
veh/h
ft (m)
(km/h)
F-F*
5890
6
45 (70)
12 (3.6 m )
R-R*
47
0
45 (70)
12 (3.6 m )
F-R*
5225
6
45 (70)
12 (3.6 m )
R-F*
879
4
45 (70)
12 (3.6 m )
Left Side (East Bound" EB")
Weaving length Posted
PHV
Lane Width
Direction
Ls
HV %
speed mi/h
veh/h
ft (m)
ft (m)
(km/h)
F-F*
480 (145 m)
5952
4
45 (70)
12 (3.6 m )
R-R*
480 (145 m)
38
0
45 (70)
12 (3.6 m )
F-R*
480 (145 m)
1086
0
45 (70)
12 (3.6 m )
R-F*
480 (145 m)
2046
4
45 (70)
12 (3.6 m )
*F-F: Freeway-Freeeway, R-R: Ramp-Ramp, F-R: Freeway-Ramp and R-F:Ramp-Freeway.
Weaving length Ls
ft (m)
460 (140 m)
460 (140 m)
460 (140 m)
460 (140 m)
NO. of
lanes
3
2
2
2
NO. of
lanes
3
2
2
2
Table 4 Al-Madeena Al-Monawra interchange : ramp required data for existing condition (2015).
Side
Right Side (West
Bound"WB")
Left Side (East Bound
"EB")
Type of
Ramp
PHV
veh/h
HV %
Merge
Diverge
Merge
Diverge
465
2765
1083
575
1
2
1
0
Posted
speed of
ramp mi/h
(km/h)
25 (40)
25 (40)
25 (40)
25 (40)
Posted
speed of
freeway
mi/h (km/h)
45 (70)
45 (70)
45 (70)
45 (70)
NO. on/offramp lanes
1
1
1
1
Table 5 Al-Madina Al-Monawra interchange: ramp required data for short-term (after 5 years - 2020)
Side
Type of
Ramp
PHV
veh/h
HV %
Right Side (West Bound
"WB")
Left Side (East
Bound"EB")
Merge
Diverge
Merge
Diverge
639
3081
1489
790
2
3
2
0
Posted
speed of
ramp mi/h
(km/h)
25 (40)
25 (40)
25 (40)
25 (40)
Posted speed
of freeway
mi/h (km/h)
NO. on/offramp lanes
45 (70)
45 (70)
45 (70)
45 (70)
1
1
1
1
Table 6 Al-Madina Al-Monawra interchange: ramp required data for medium-term (after 10 years 2025).
Side
Right Side (West
Bound "WB")
Left Side (East
Bound"EB"
Type of
Ramp
PHV
veh/h
HV %
Merge
Diverge
Merge
Diverge
879
5225
2046
1086
4
6
4
0
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Posted
speed of
ramp
mi/h
(km/h)
25 (40)
25 (40)
25 (40)
25 (40)
Posted
speed of
freeway
mi/h
(km/h)
45 (70)
45 (70)
45 (70)
45 (70)
NO.
on/offramp
lanes
1
1
1
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Evaluation and Improvement of Ramp Junctions on Multilane Urban Arterial Streets
4. FINDINGS AND RESULTS DISCUSSION
4.1. The analysis of weaving area:
The HCS- 2010 software programs were applied for existing conditions, short-term conditions
and medium-term conditions for the weaving segments of Al-Madina Almonawra
interchange.
The output results were shown in Table 7, Table 8 and Table 9 respectively.
Figure 2 shows the formulation of weaving area.
The result in Table 7 shows that all segments in each direction operate at LOS F for the
existing condition.
The result in Table 8 shows that all segments in each direction will operate at LOS F for
the short-term conditions after 5 years; with higher (v/c) ratio.
The result in Table 9 shows that the all segment in each direction will be operated at LOS
F for the medium-term conditions after 10 years with the increased (v/c) ratio.
Table 7 Results of HCS 2010 for Al-Madina Al-Monawra interchange weaving segments for the
existing condition.
Segment
Right side( West Bound)
Left side (East Bound)
Weaving
Flow
Rate
veh/h
6708
5083
Weaving
segment
Capacity
CW: veh/h
4689
5445
Weaving
Segment
v/c ratio
1.43
0.933
Weaving
Segment
Speed
mi/h
26
Density
pc/mi/ln
LOS
64
F
F
Table 8: Results of HCS 2010 for Al-Madina Al-Monawra interchange weaving segments for the
short term (2020) conditions
Weaving
Flow Rate
veh/h
Segment
Right side( West Bound)
Left side( East Bound)
9220
6986
Weaving
Segment
Capacity
CWveh/h
4666
5650
Weaving
Segment
v/c ratio
1.976
1.2
Weaving
Segment
Speed
mi/h
-
Density
pc/mi/ln
LOS
-
F
F
Table 9: Results of HCS 2010 for Al-Madina Al-Monawra interchange weaving segments for the
medium term conditions
Segment
Right side( West Bound)
Left side( East Bound)
Weaving
Flow
Rate
veh/h
12675
9603
Weaving
Segment
Capacity
CWveh/h
4599
5368
Weaving
Segment
v/c ratio
2.756
1.78
Weaving
Segment
Speed
mi/h
-
Density
pc/mi/l
n
LOS
-
F
F
Figure 2 Formation of Weaving Segment (Source HCM-2010)
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Figure 3 Merge Influence Area of on-ramp (Source HCM-2010)
Figure 4 Diverge Influence Area of of-ramp (Source HCM-2010)
Figure 5: Sketch of the geometric condition after improvement of weaving area.
4.2. The analysis of merge and diverge ramps
Four leg ramps exist in Al-Madina Almonawra cloverleaf interchange. All of these ramps
(merge and diverge) were analyzed with HCS-2010 methodology for existing, short and
medium-term conditions as shown in Tables 10, 11 and12 .
Figure 3 and Figure 4 show the merg and diverge influence area for on ramp and off ramp
of each approach of the selected interchange.
5. DISCUSSION OF RESULTS
The analysis of the selected highway shows that some segments of ramp junctions are
operating at LOS- F or at LOS-E.
For the purpose of improving the LOS. The following suggestions could be applied:

Increase the width of multilane street by adding collector-distributer(C-D) roadway.

Increase the number of lane of multilane street to be 4 lanes by decrease lane width to (3.3m)
in each direction at upstream and downstream.

Adding auxiliary lane off/on-ramp to all segments to be tow on/off-ramp lane.
Figure 5 shows sketch for improvement the geometric condition after improvement of
weaving area.
Based on the above suggestions, the following four tables show that the segments
operating at LOS E and LOS F could be improved to better LOS.
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Evaluation and Improvement of Ramp Junctions on Multilane Urban Arterial Streets
Table 13 shows the output results for improving the selected cloverleaf interchange within
the existing, short and medium term periods of weaving areas. The results of improvement
show that the existing condition improved from LOS F to LOS B for each direction; with
lower (v/c) ratio. In short-term the LOS improved from LOS F to the LOS C. While in
medium-term the LOS remained at LOS F.
According to (Momani, 2016) in here MSc thesis, it was recommended to reduce 25% of
the future demand as one of the demand reduction strategy in Amman area for future traffic
condition. Therefore, the growth factor will be changed to (5 %) instead of (6.57 %) for next
suggested improvement.
As this strategy will be applied in medium –term. The LOS improved from LOS F to LOS
D for each direction as shown in Table 14.
Table 15 shows the improvement under the short-term for the selected cloverleaf
interchange of merge and diverge areas. The right side merge ramp improved from LOS F to
the LOS B, and diverge ramp improved from LOS F to the LOS C, The left side merge ramp
improved from LOS F to the LOS B and diverge ramp are improved from LOS C to the LOS
B.
Table 16 shows the improvement for the medium-term for the studied cloverleaf
interchange of merge and diverge areas. The right side merge ramp improved from LOS F to
the LOS B and diverge ramp improved from LOS F to the LOS D. The left side merge ramp
improved from LOS F to the LOS D and diverge ramp improved from LOS D to the LOS C.
Table 10: Results of HCS 2010 for Al-Madina Al-Monawra interchangemerge and diverge ramp for
the existing conditions.
Segment
Right side
(WB*)
Left side (EB*)
Ramp
Type
Flow
Rate for
Multilan
e pc/h
NO. of
lane of
Multila
ne
Flow
Rate For
ramp
pc/h
Flow
Rate in
lane 1and
2 v12
(pc/h)
Merge
Diverge
Merge
Diverge
3422
3422
3441
3441
3
3
3
3
508
3020
1183
625
3422
3235
3066
2442
Space mean
Speed in
Ramp
Influence
Area SR
mi/h
44
42
43
44
Density
pc/mi/ln
LOS
33
27.9
36
21
D
C
E
C
Table 11 Results of HCS 2010 for Al-Madina Al-Monawra interchangemerge and diverge ramp for
short-term conditions (2020).
Segment
Right side
(WB*)
Left side
(EB*)
Ramp
Type
Flow
Rate for
Multilane
pc/h
NO. of
Lane of
Multilane
Flow Rate
For
Ramp
pc/h
Flow Rate
in Lane
1and 2 v12
(pc/h)
Merge
Diverge
Merge
Diverge
4727
4727
4745
4745
3
3
3
3
702
4193
1635
859
4727
4433
4754
3202
Space
mean
Speed in
Ramp
Influenc
e Area
mi/h
41
42
37
43
Density
pc/mi/ln
LOS
45
38
51
27
F
F
F
C
* WB:West Bound and EB:East Bound.
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Table 12: Results of HCS 2010 for Al-Madina Al-Monawra interchange merge and Diverge ramp for
medium-term condition (2025).
aRmp
Type
Flow
Rate for
Multilane
pc/h
Segment
Merge
6594
Right side
(WB*)
Diverge
6594
Merge
6599
Left side
(EB*)
Diverge
6599
*WB:West Bound and EB:East Bound
NO. of
Lane of
Multila
ne
Flow Rate
For ramp
pc/h
Flow
Rate in
Lane
1and 2 v12
(pc/h)
3
3
3
3
994
5850
2268
1180
6594
6093
6599
4110
Space
mean speed
in Ramp
Influence
Area SR
mi/h
21
41
38
43
Density
pc/mi/ln
LO
S
61
52
71
35
F
F
F
D
Table 13: Improvement for Al-Madina Al-Monawra interchange weaving area AccordingHCS2010output result.
Time Period
Segment
Right side
Left side
Right side
Left side
Right side
Left side
Existing
Short-term
Medium-term
Weaving
Flow Rate
veh/h
3308
3337
4547
4587
6250
6306
Weaving
Segment
Capacity
CWveh/h
8265
8310
8225
8269
8105
8188
Weaving
Segment
v/c ratio
0.4
0.4
0.553
0.555
0.771
0.77
Weaving
Segment
Speed
mi/h
41
41
39
39
37
37
Density
pc/mi/ln
LOS
20
20
29
29
43
43
B
B
C
C
F
F
Table 14: Improving Al-Madina Al-Monawra interchange weaving area by reduce growth factor in
medium-term according HCS- 2010output result.
Time period
Medium- term
Segment
Right side
Left side
Weaving
Flow
Rate
veh/h
5350
5398
Weaving
Segment
Capacity
CWveh/h
8144
8229
Weaving
Segment
v/c ratio
0.657
0.656
Weaving
Segment
Speed
mi/h
38
38
Density
pc/mi/ln
LOS
35
35
D
D
Table 15: Improvement merge and diverge ramps for Al-Madina Al-Monawra interchangefor the
short-term (2020) according HCS-2010output result.
RRamp
Type
Segment
Flow
Rate for
Multilane
pc/h
Merge
4727
Right side
(WB*)
Diverge
4727
Merge
4754
Left side
(EB*)
Diverge
4754
*WB:West Bound and EB:East Bound
NO. of
Lane of
Multilan
e
Flow
Rate For
Ramp
pc/h
Flow
Rate in
Lane
1and 2
v12 (pc/h)
4
4
4
4
461
2096
818
429
988
2780
994
1553
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Space Mean
Speed in
Ramp
Influence
Area SR
mi/h
44
43
44
43
Density
pc/mi/l
n
LO
S
14
25
17
17
B
C
B
B
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Evaluation and Improvement of Ramp Junctions on Multilane Urban Arterial Streets
Table 16: Improvement merge and diverge ramps for Al-Madina Al-Monawra interchange for the
medium-term (2025) According HCS- 2010output result.
RRamp
Type
Segment
Flow
Rate for
Multilane
pc/h
Merge
6594
Right side
(WB*)
Diverge
6594
Merge
6599
Left side
(EB*)
Diverge
6599
*WB:West Bound and EB:East Bound
NO. of
Lane of
Multilane
Flow Rate
For
Ramp
pc/h
Flow
Rate in
Lane
1and 2 v12
(pc/h)
4
4
4
4
498
2925
1134
590
1378
3879
1379
2152
Space
Mean
Speed in
Ramp
Influence
Area SR
mi/h
44
43
44
43
Density
pc/mi/ln
LO
S
17
34
32
23
B
D
D
C
6. DEVELOPMENT MANAGEMENT PROGRAM
The main achievement of this study is to improve LOS to better traffic flow for the selected
interchange. This improvement is achieved by increase number of lanes of multilane street,
decreasing lane width to decrease density, Also adding collector-distributor roadway (C-D) to
decrease weaving maneuver drive. For merge and diverge ramps adding on-ramps off-ramps
to increase capacity of ramp junction. The LOS(F or E) will be improved to to better LOS (C
or D) respectively. This improvement lead to decrease congestion, stops, delay time, air
pollution, and increase safety for the drivers with better travel time.
Meanwhile, cost estimation for such improvements is out of scope of this study, and it is
recommended for any future work in this field. However, the results of management flow
diagrams to develop existing, short-term and medium term condition for the weaving areas as
well as the ramp-junction based on analysis and improvement of the output results by using
highway capacity software (HCS2010) for the selected interchange are shown in Figures 6
and Figures 7respectively.
Figure 6 shows a flow diagram of the weaving management components for the selected
cloverleaf interchange. The existing traffic condition is operated at LOS F for each segment,
and for short term and medium-term will be operated at LOS F. Due to the improvement of
the geometric condition, the existing condition will be operated at LOS B for each segment.
The short term will be operated at LOS C for each segment. The medium-term will be
operated at LOS F. By reducing 25% of future demand as one of the strategy of demand
reduction, the medium term will be operated at LOS D. Similarly, Figure 7 shows a flow
diagram of the ramp-junction management components for the selected cloverleaf
interchange.
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Majed Msallam, Basim Jrew, Raed Nazzal Al-Muhanna, Mohammed Jabbar Hussein
Weaving of Cloverleaf Interchange
Data collecton
Data analysis
Existing condition (2015)
Left side (EB)
LOS F
Right side
(WB)
LOS F
Short-term
(2020)
Right side
(WB)
Left side (EB)
LOS F
Medium-term
(2025)
Left side (EB)
LOS F
Right side
(WB)
LOS F
Existing condition improvement
Left side (EB)
LOS B
Right side
(WB)
LOS B
Short-term improvement
Left side (EB)
LOS C
Right side
(WB)
LOS C
Medium-term improvement
Left side (EB)
LOS D
Right side
(WB)
LOS D
Figure 6 The flow diagram of improving weaving area for Al-MadinaAl-MonawraCloeverleaf
interchange
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Evaluation and Improvement of Ramp Junctions on Multilane Urban Arterial Streets
Ramp Junction Cloverleaf
Interchange
Data collection
Data analysis
Existing condition
(2015)
Right side
(WB)
Merge LOS D
Diverge LOS C
Left side (EB)
Merge LOS E
Diverge LOS C
Short-term
(2020)
Right side (WB)
Merge LOS F
Diverge LOS F
Medium-term
(2025)
Right side (WB)
Merge LOS F
Diverge LOS F
Left side (EB)
Merge LOS F
Diverge LOS D
Medium-term
improvement
Left side (EB)
Merge LOS D
Diverge LOS C
Short-term
improvement
Right side
(WB)
Merge LOS B
Diverge LOS D
Left side (EB)
Merge LOS B
Diverge LOS B
Right side
(WB)
Merge LOS B
Diverge LOS C
Figure 7 The flow diagram for improving ramp-junction of Al-Madina Al-Monawra cloverleaf
interchange
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Majed Msallam, Basim Jrew, Raed Nazzal Al-Muhanna, Mohammed Jabbar Hussein
7. CONCLUSIONS
7.1. Weaving area

For the studied cloverleaf interchange, the LOS F (failure or breakdown) traffic flow was
found for the existing condition, short- term and medium-term condition in all directions.

Due to the improvement of management program the existing condition of each direction will
be operated at LOS B.

Due to the improvement of management program the short-term condition of each direction
will be operated at LOS C.

Due to the improvement of management program the medium-term condition of each
direction will be operated at LOS D.
7.2. Ramp-junction

For the studied cloverleaf interchange in the existing condition, the LOS E was found at the
left side (EB) for the merge ramp. In short-term and medium-term, the LOS F was found at
the right side (WB) in all direction, and left side (EB) the LOS F was found in merge ramp.

Due to the improvement of management program the short-term of the right side (WB) merge
ramp will be operated at LOS B and diverge ramp will be operated at LOS C. The left side
(EB) for each direction will be operated at LOS B.

Due to the improvement of management program the medium-term of the right side (WB)
merge ramp will be operated at LOS B and diverge ramp will be operated at LOS D. The left
side (EB) merge ramp will be operated at LOS D and diverge ramp will be operate at LOS C.
8. RECOMMENDATIONS
The following recommendations are driven:

Increase number of lane on urban multilane highway on upstream and downstream of each
interchanges in order to operate as expressway. Therefore, the capacity and LOS will be
improved in the selected cloverleaf interchanges.

Adding collector-distributor road (C-D) to the cloverleaf interchanges will improve
capacity and LOS for both weaving area and ramp-junction in a multilane highway

Adding auxiliary lane to the ramp-junction with the (C-D) roadway will increase the capacity
and improve LOS of the cloverleaf interchanges.

It is recommended to combine the policy on geometric of highway and street AASHTO with
HCM methodology to improve the cloverleaf interchanges at multilane highway capacity and
LOS.

It is recommended to use reduction demand strategy by 25% for the medium- term condition
in order to reduce the growth traffic factor.

The improvement leads to decrease congestion, stops, delay time, air pollution and also
increase safety for the driving with better travel time. Cost estimation for such improvements
is recommended for any future work in this field.

It is recommended to use intelligent transportation system (ITS) as alternative tools to
improve ramp and ramp junction such as ramp metering or junction control. The objective of
junction control through either static or real-time means the best management of recurrent
congestion by making traffic flow more uniform, utilizing more effectively for the existing
roadway capacity, and improving traffic safety.
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the
Evaluation and Improvement of Ramp Junctions on Multilane Urban Arterial Streets

More studies are required on other major cloverleaf interchanges in Amman-Jordan in urban,
suburban and rural areas.
REFERENCES
[1]
American Association of State Highway and Transportation Officials.A Policy on
Geometric Design of Highways and Streets. Washington, D.C., 2011.
[2]
Highway Capacity Manual, Special Report 209. Transportation Research Board,
Washington DC (1985).
[3]
Momani M, Wasef. (2016). Evaluation and improvement of transportation demand
management (TDM) in Jordan, MSc, ISRA University.
[4]
TRB. Highway Capacity Manual, HCM2010. Transportation Research Board, Washington
DC .
[5]
TRB.Highway Capacity Manual.HCM 2000.Transportation Research Board, National
Research Council, Washington, DC.
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