Civil 150 project

INTERSECTION DESIGN AND ANALYSIS

CE 150 CLASS PROJECT ASSIGNMENT SUMMER 2014

SR 96 – X STREET 10-SJ-96 P.M. 8.341

University of the Pacific

CE 150 Class Project

INTERSECTION OF STATE ROUTE 96 AT X STREET

Improvement Study

10-SJ-96 PM 8.34

Prepared by:

Traffic-letesAlaina RossiDylan DibbleBryant Arias

Reviewed by:Dr. Wang

July 2014



SR 96 – X STREET 10-SJ-96 P.M. 8.342

TABLE OF CONTENTS

Fig. 1. The Intersection of SR 96 and X StreetFig. 2. Traffic conditions at the intersection 2013Fig. 3. Traffic conditions at the intersection 2033Fig. 4. Vehicle trajectory Horizontal CurveFig. 5. EBLT Horizontal CurveFig. 6. Bridge Vertical CurveFig. 7. Vehicle Trajectory 2033Fig. 8. EBLT 2033Fig. 9. Signaling Information 2013Fig. 10. Signaling information 2033Table 1. Velocity, SSD, R, M, L, Rv, and ∆𝑠Table 2.1. Signal Timing, Delay, LOS 2013 AMTable 2.2. Signal Timing, Delay, LOS 2013 PM

Table 2.3. Signal Timing, Delay, LOS 2033 AMTable 2.4. Signal Timing, Delay, LOS 2033 PMTable 2.5. Signal Timing, Delay, LOS 2033 AM Alternative ATable 2.6. Signal Timing, Delay, LOS 2033 PM Alternative ATable 2.7. Signal Timing, Delay, LOS 2013 AM Alternative ATable 2.8. Signal Timing, Delay, LOS 2013 PM Alternative ATable 2.9. Signal Timing, Delay, LOS 2033 AM Alternative BTable 2.10. Signal Timing, Delay, LOS 2033 PM Alternative B

Page

PURPOSE………………………………………………………………………… 3BACKGROUND………………………………………………………………… 3

Existing GeometricsExisting Traffic Volumes Existing signal information

LOS ANALYSIS FOR THE EXISTING INTERSECTION………………….……4IMPROVEMENT ANALYSIS………………………………………………..….. 5

Year 2033 Traffic Demand Forecast Basic Assumptions for the AnalysisAlternatives

-Additional lanes-Phase changes-Design speed

SUMMARY………………………………………………………………………. 11REFERENCES……………………………………………………………………. 12APPENDICES……………………………………………………………………... 13

A -- TABLES AND EQUATIONS…………………………...………... 13B -- ALTERNATIVES AND ATTEMPTS……………………………. 14 C -- HORIZONTAL & VERTICAL CURVES 2013………………...… 15D -- HORIZONTAL & VERTICAL CURVES 2033…………………. 18E -- SIGNALING INFORMATION…………………………………….20F -- PEDESTRIAN CROSSING TIME…………………………………22G -- PAVEMENT DESIGN…………………………………………….. 23H -- ALTERNATIVE EBLT……………………………………….……24I -- AUTOCAD…………………………………………………………25



SR 96 – X STREET 10-SJ-96 P.M. 8.342

PurposeThe CE150 class project is to provide an opportunity to use everything learned from class to designing a signalized intersection, and evaluating its level of service.

BackgroundExisting Geometries SR 96 is a two lane state highway. It is a commuter route with morning and evening peaks serving home to work trips in San Joaquin County. X Street is a two lane local road. As shown in Figure (Fig.) 1, the intersection of SR 96 and X Street is currently an isolated 3-phase signal controlled intersection. The existing left-turn pockets on eastbound (EB) and westbound (WB) SR 96 are both about 150 feet (ft.) long. All lanes are 12 ft. wide. The speed limits are 50, and 30 miles per hour (mph) for SR 96 and X Street, respectively. Evaluation horizon is 20 years, or till the end of year 2033. The intersection is located in a flat area with almost zero percent grades. Assume zero elevation at the center of the intersection. The railroad requires a clearance of 22.5 ft. The bridge structure has a depth of 6 ft. A railroad intersects with X Street at 4000 ft. north of the intersection. PHF=0.85 All truck traffic has one 32 kips single axle, and a 46 kips tandem axle. Existing traffic volumes growth rate is 4% per year, including truck traffic. The saturation flow rate is 1700 vphpl for through and right turn movements. For left turn movements, the saturation flow rate is 1500 and 450 vphpl for protected and permitted control, respectively.

Fig. 1. The Intersection of SR 96 and X Street

Residence

SR 96

To Sacramento

X Street

To Stockton

Not to scale.

A

B



SR 96 – X STREET 10-SJ-96 P.M. 8.343

Existing Traffic VolumesAs shown in Fig. 2, the existing traffic movements for both A.M. and P.M. peak hours are collected on May 23, 2014, with a truck percentage of 8%.

Figure 2. Traffic conditions at the intersection 2013

LOS Analysis for the Existing Intersection

The Level of Service for the 2013 traffic flow in the existing intersection is LOS C for AM and PM peak traffic volume.

Alternative AThe Level of Service for the 2013 traffic flow in the intersection, with the design change and added lanes, is LOS C for AM and PM peak traffic volume.

AM peak turning movement (existing 2014) PM peak turning movement (existing 2014)

120 80

291

5582 636

3818323312

91

20120

49

41

22 55

118

69253 431

148510770112

41

68738

109

113



SR 96 – X STREET 10-SJ-96 P.M. 8.344

Improvement Analysis

Year 2033 Traffic Demand ForecastIn Fig. 2, the AM and PM peak traffic volume is shown. The traffic demand increases by 4% each year, as shown.

Figure 3. Traffic conditions at the intersection 2033

Basic Assumptions for the AnalysisOur assumptions for the analysis are:

-the road runs above the railroad and requires a positive to negative grade for the vertical curve of the road. -the stopping sight distance begins once the vehicle sees the left turn lane and goes from point A, , to turn and then accelerates to to 𝑣1 = 50𝑚𝑝ℎ 𝑣2 = 25𝑚𝑝ℎ 𝑣3 = 30𝑚𝑝ℎ match the speed limit of X street and cross the railroad.-Stopping sight distance is 500ft for the vertical curve on X st, the horizontal distance is set at 1000ft in order to minimize the grade. It does not interfere with the intersection.

Table 1. Velocity, SSD, R, M, L, Rv, and ∆𝑠

velocity velocity SSD R M L Rv ∆𝑠mph fps ft ft ft ft ft °

20 29.4 115 98 46.5184451 153.93804 92 71.6197243825 36.75 155 98 46.5184451 153.93804 92 95.8330185030 44.1 200 98 46.5184451 153.93804 92 124.5560424

AM peak turning movement (existing 2033) PM peak turning movement (existing 2033)

263 175

638

11

1275 13938340151026

199

44244

107

90

48 120

258

151554 944

32411171687245

90

1491583

239

247



SR 96 – X STREET 10-SJ-96 P.M. 8.345

For the 2013 AM and PM Traffic Flow, shown in table 2.1 and 2.2, the summary of delay and Level of Service calculations for the intersection of X Street and SR 96 is calculated for the given intersection on Fig. 1.

Table 2.1. Signal Timing, Delay, LOS 2013 AM

Table 2.2. Signal Timing, Delay, LOS 2013 PM



SR 96 – X STREET 10-SJ-96 P.M. 8.346

The 2033 AM and PM Traffic Flow are shown in tables 2.3 and 2.4 with the same design plan as the given intersection in Fig. 1. However, a negative was calculated for AM and LOS F 𝐶𝑚𝑖𝑛

(failure) was determined for both AM and PM as there were only three critical lane groups for such a heavy traffic flow.

Table 2.3. Signal Timing, Delay, LOS 2033 AM

Table 2.4. Signal Timing, Delay, LOS 2033 PM



SR 96 – X STREET 10-SJ-96 P.M. 8.347

We added another through lane Eastbound and Westbound and added a permitted left turn lane Southbound and Northbound that is still in the same phase as all NB and SB approaches. This raised our Saturation Flow and Lowered the LOS to C for AM and PM.

Table 2.5. Signal Timing, Delay, LOS 2033 AM Alternative A

Table 2.6. Signal Timing, Delay, LOS 2033 PM Alternative A



SR 96 – X STREET 10-SJ-96 P.M. 8.348

The changes must be reflected on the 2013 design as well since we must design for the year 2033. With the lane changes we have, 2013 AM and PM LOS drop drastically.

Table 2.7. Signal Timing, Delay, LOS 2013 AM Alternative A

Table 2.8. Signal Timing, Delay, LOS 2013 PM Alternative A



SR 96 – X STREET 10-SJ-96 P.M. 8.349

Another Alternative we used was to make all approaches the same phase such that Eastbound LT and T/R shared the same phase, Westbound LT and T/R shared the same phase, and all Northbound and Southbound approaches shared the same phase. This gave us a longer cycle length and more delay, but kept all approaches at an LOS below F.

Table 2.9. Signal Timing, Delay, LOS 2033 AM Alternative B

Table 2.10. Signal Timing, Delay, LOS 2033 PM Alternative B



SR 96 – X STREET 10-SJ-96 P.M. 8.3410

Summary

We calculated the flow rates on the condition that the level of service would satisfy driver

efficiency until the year 2033. If we kept the original 2013 design, the intersection would have a

poor level of service (F) and would cause major delays. Two alternatives were used for design

of this intersection. Alternative #1 consisted of adding 1 lane to each direction of each leg which

would increase capacity and decrease delay. Alternative #2 involved re-arranging the light

phasing to strictly east bound in one group, as well as west, north and south.

For our Vertical Curve design, we used 1000’ for the Length. This is so that the 3○ grade

fits right up to the lateral clearance. This minimizes the incline that the driver feels on the road,

thus making it easier for smaller cars.

Pavement design consists of having to choose the material used for the surface of the

road. We decided to use flexible pavement and assumed a structural number (SN) of 4 with a

95% reliability. The given information of traffic flow allowed us to calculate a W18 of 25.7x107

which resulted in a true SN of 5.44. We estimated a 6 inch surface, 11 inch base and 12 inch

sub-base, according to this SN. The Design was determined for a 20 year service life.



SR 96 – X STREET 10-SJ-96 P.M. 8.3411

References

Mannering, Fred L., and Scott S. Washburn. Principles of Highway Engineering and Traffic Analysis. Hoboken, NJ: Wiley, 2013. Print.

Aashto Lrfd Bridge Design Specifications. Washington, D.C: American Association of State Highway and Transportation Officials, 1994. Print.

Dr. Zhongren Wang



SR 96 – X STREET 10-SJ-96 P.M. 8.3412

AppendixTables and equations

𝑅𝑣 =𝑣2

𝑔(𝑓𝑠 +𝑒

100)

𝐿 =𝜋

180𝑅∆

𝑅 = 𝑅𝑣 ‒ 6

∆𝑠 =180 𝑆𝑆𝐷

𝜋𝑅𝑣

𝑓𝑠 =𝑣2

𝑅𝑣𝑔, at intersection𝑒 = 0

𝐻1 = 8 𝑓𝑡.𝐻2 = 2 𝑓𝑡.

𝑔𝑖 = (𝑣𝑠)𝑐𝑖( 𝐶

𝑋𝑖)

𝑌 = 𝑡𝑟 +𝑉

2𝑎 + 2𝑔𝐺

𝐴𝑅 =𝑤 + 𝑙

𝑉𝐶 = 𝑟 + 𝑔

𝐺𝑝 = 3.2 +𝐿𝑆𝑝

+ (0.27𝑁𝑝𝑒𝑑) 𝑓𝑜𝑟 𝑊𝑒 ≤ 10𝑓𝑡.

log10 𝑊18 = 𝑍𝑟𝑆𝑜 + 9.36[log10 (𝑆𝑁 + 1)] ‒ 0.20 +log10 [Δ𝑃𝑆𝐼

2.7 ]0.40 + [ 1094

𝑆𝑁 + 1]5.19+ 2.32log10 𝑀𝑅 ‒ 8.07



SR 96 – X STREET 10-SJ-96 P.M. 8.3413

Other alternatives and attempts:

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Civil 150 project