ECG504

ECG504 HIGHWAY AND TRAFFIC ENGINEERING LABORATORY

1.0 INTRODUCTION

A Level of Service (LOS) is a letter designation that describes a range of operating conditions on a particular type of facility. It is defined as a qualitative measures that characterize operational conditions within a traffic stream and their perception by motorists and passengers.

The critical point in this definition is the need to define service quality in terms that are perceived by drivers and passengers. Several key measures are used to describe service quality in these terms:i. Speed and travel time. Drivers and passengers are keenly aware of the amount of time to get from place to place.ii. Density. Density describes the proximity of vehicles to each oter in the traffic stream and reflects ease of maneuverability in the traffic stream, as well as psychological comfort of drivers.iii. Delay. At intersections, delay is the average stopped time per vehicle traversing the intersection. Delay times are portions of of travel time that are particularly obvious to drivers and are particularly obvious to drivers and particularly annoying or frustrating.

There are six levels of service in junction capacity analysis, represented by A to F, with A is the best while F is the worst. In this practical analysis, we are using manual calculations to describe the LOS of an unsignalized junction based on the data obtained from the previous test.2.0 OBJECTIVE

The objectives of the test are:i. To determine the capacity and the LOS for the unsignalised intersection. ii. To ensure all roads are safe for all road users.

3.0 APPARATUS

There is no apparatus needed in this test considering the data used are obtained from the previous test, junction volume study.

4.0 PROCEDURE

i. Identify movements to be served and assign hourly traffic volumes per lane. This is the only site-specific data that must be provided. The hourly traffic volumes are usually adjusted to represent the peak 15-minute period. The number of lanes must be known to compute the hourly volumes per lane.ii. Arrange the movements into the desired signal phasing plan. The phasing plan is based on the treatment of each left turn (protected, permitted, etc.). The actual left-turn treatment may be used, if known. Otherwise, the likelihood of needing left-turn protection on each approach will be established from the left-turn volume and the opposing through traffic volume.iii. Determine the critical volume per lane that must be accommodated on each phase. Each phase typically accommodates two nonconflicting movements. This step determines which movements are critical. The critical movement volume determines the amount of time that must be assigned to the phase on each signal cycle.iv. Sum the critical phase volumes to determine the overall critical volume that must be accommodated by the intersection. This is a simple mathematical step that produces an estimate of how much traffic the intersection needs to accommodate.v. Determine the maximum critical volume that the intersection can accommodate: This represents the overall intersection capacity. The HCM QEM suggests 1,710 vph for most purposes.vi. Determine the critical volume-to-capacity ratio, which is computed by dividing the overall critical volume by the overall intersection capacity, after adjusting the intersection capacity to account for time lost due to starting and stopping traffic on each cycle. The lost time will be a function of the cycle length and the number of protected left turns.vii. Determine the intersection status from the critical volume-to-capacity ratio.

5.0 RECOMMENDATION

i. Students should wear proper attire when entering the lab such as the lab jacket, long trousers, and fully covered shoes. The safety vest is compulsory to wear before start the experiment.ii. Students are not allowed to play around while they are in the lab to avoid accident and severe injuries.iii. Choose the spot for taking the reading wisely and avoid sharp corner spot in order to prevent dangerous act.iv. The instructions, objectives of the experiment, and materials were understood before beginning work in lab. v. Use clean sheet for recording data in order to prevent errors.vi. Communicate wisely among group members.vii. The student must determine the accurate critical volume per lane on each phase to get which movement are critical.viii. Carefully determine the critical volume.ix. Calculate lost time carefully to determine the cycle length.x. Intersection status must be done carefully because it might make the main answer is wrong.

6.0 RESULT

CAPACITY AND LOS FOR UNSIGNALISED JUNCTIONMovement No.234579

Volume (vph)551197612521414

Vol ( pcph)43.598.5

Input volume data.VOLUMEMovement 4Movement 7Movement 9

Car/Taxi3743

Van (LGV)000

Van & Lorry (MGV)000

Lorry (HGV)000

Bus000

Motorcycle131011

Volume of the conflict movement.

Calculation of volume each conflict point :Movement 4 :

Movement 7 :

Movement 9 :

Road volume 4:

Road volume 7 :

Road volume 9 :

Movement no.Volume , V(pcph) (pcph)Shared capacity, (pcph) = Level of Service, LOS

43.5525481.5A

9335.8326.8B

8.5335.8327.3B

LOS Criteria for Unsignalised IntersectionsRESERVE CAPACITY (PCPH)LOSEXPECTED DELAY TO MINOR ROAD TRAFFIC

400ALittle or No Delay

300-399BShort Traffic Delays

200-299CAverage Traffic Delays

100-199DLong Traffic Delays

0-99EVery Long Traffic Delays

*F*

Adopted from: A Guide to the Design of At-Grade Intersections in Arahan Teknik( Jalan ) 11/87, Kuala Lumpur : Jabatan Kerja Raya Malaysia.Level of Service Criteria for Unsignalised IntersectionAREASCATEGORY OF ROADLOS

RURALExpresswayC

HighwayC

PrimaryD

SecondaryD

MinorE

URBANExpresswayC

ArterialD

CollectorD

Local StreetE

Adopted from: A Guide to the Design of At-Grade Intersections in Arahan Teknik( Jalan ) 11/87, Kuala Lumpur : Jabatan Kerja Raya Malaysia.

7.0 DISCUSSION

Capacity analysis was carried out to identify the ability of the roadway to accommodate traffic. Level of Service (LOS) is used to classify the varying conditions of traffic flow that takes place on highway. Previous calculated values from Traffic Volume Study are used in order to determine LOS of the selected location.Traffic volume study was carried out to count the number of vehicles passing a specific reference point on a road section within a specified period of time. Each mechanical hand tally counter represents each flow.

The study shows that the number of each type of vehicles passes from each direction, as well as the number of each vehicles passes from each direction in every 15 minutes within an hour, from 0915 a.m. up to 1015 a.m. Throughout the observation, the traffic volume increases from 09:15 to 09:30 and from 10:00 to 10:15. While, the traffic volume decreases from 09:30 to 10:00. Direction 3 recorded as the highest number of vehicles travelled the selected location which is 587 vehicles in total. At the same time, Direction 1 recorded 267 vehicles in total which falls under the second highest vehicle volume passes the location. In contrast, both Direction 5 and Direction 6 recorded as the lowest vehicle volume travelled the same location throughout the study, which are 18 and 17 in total respectively. This indicates that there are more vehicle travelled in the main road (from Gate 1 and Gate 2) compared to the minor road (from Laboratory of Civil Engineering).

8.0 CONCLUSION

Based on the data collected and analyzed from traffic volume study, the traffic volume observed in the selected location can be considered falls under LOS B. From the analysis of the data collected, the most critical time period is from 10:00 to 10:15 a.m., where the traffic volume in the intersection increases.In conclusion, after completed the analysis on traffic volume, the final Level of Service were obtained. For all lane, the LOS are A and B which this indicate stable flow with operating speeds with little or no restrictions and short traffic delays . The traffic will hardly delayed and did not affect the intersection operations. Speeds and volume can drop to very low and also stoppages still can occur due to busses stopping in the road with single lane.

9.0 REFERENCES

i. Tey Li Sian, S. Z, & Yusof, M (200%). Highway and Traffic Laboratory Manual.Shah Alam: FKA UITM Malaysia.ii. J.Garber, N, & A.Hoel, L (2003). Traffic and Highway Engineering. Virginia, US:Brooks/cole.iii. Currin, T. R. 2001. Turning Movement Counts. In Introduction to Traffic Engineering: A manual fo Data collection and Analysis, ed. B. Stenquist. Stamford, Conn: Wadsworth Group. PP. 13-23iv. FHWA. 201. Manual on Uniform Traffic Control Devices: Millennium Edition. Washington, D.C: Federal Highway Administration, U.S. Department of Transportation

10.0 APPENDIX

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