Traffic Evaluation DONE

TRAFFIC EVALUATION OF WALTER S. DAVIS & 39TH AVE.Group Members Favorite Professor•Preston Bailey Dr. Deo Chimba•James Jones•Manal Sankari•Caleb Simpkins

INTRODUCTION Analyzed the intersection of Walter S. Davis

Blvd and 39th Ave. Intersection is located within the Northwest

corner of Tennessee State University’s Campus Generally speaking, traffic at this area is slightly

lower relative to other intersections around the university

For the sake of checking for improvements, this intersection was analyzed to calculate Level of Service (LOS); this measurement, ranging from grade A through grade F, will determine if improvements are needed.

INTERSECTION OF WALTER DAVIS &39TH AVE

WALTER S. DAVIS BLVD AND 39TH AVE. Recorded traffic volumes at morning and

evening peak hours. Collected traffic data using Turning

Movement Counting machine. Evaluated statistics using Synchro Planning

and Analysis Software

GEOMETRIC DATA Assumptions:

All lanes are 12 ft wide Grade is 2% No existing storage lanes No adjacent parking lanes

SIGNALIZATION DATA Ideal saturation flow is 1900 vphpl 2 bus block per hour Pedestrian conflict is 20 per hour Yellow time is 3.5 seconds for all movements All red time is 1.5 seconds for all movement Minimum split is 8 seconds for all left-turn

movement Minimum slit is 20 seconds for all through

and right-turn movements

TRAFFIC DATA Two hours of data were collected for each AM

and PM peak hour turning movement counts (TMC) traffic at 39th and Walter S. Davis Blvd

AM peak was taken between 7 AM and 9 AM (Thursday)

PM peak was taken between 4 PM and 6 PM (Thursday)

Assumptions: K-factor is 10% Truck factor is 2%

TRAFFIC AND SPEED CHARACTERISTICS

Traffic CharacteristicsIdentified AM and PM peak hours by intersection

TRAFFIC AND SPEED CHARACTERISTICS

From the peak hours identified above, AM and PM peak hour volumes, respectively, were calculated by approach; (e.g. EB, WB,NB, and SB) for the intersection

TRAFFIC AND SPEED CHARACTERISTICS

1:00 A

M

2:00 A

M

3:00 A

M

4:00 A

M

5:00 A

M

6:00 A

M

7:00 A

M

8:00 A

M

9:00 A

M

10:00

AM

11:00

AM

12:00

PM

1:00 P

M2:0

0 PM3:0

0 PM4:0

0 PM5:0

0 PM6:0

0 PM7:0

0 PM8:0

0 PM9:0

0 PM

10:00

PM

11:00

PM

12:00

AM0

200

400

600

800

1000

1200

1400

1600

1800

Variation of Traffic with Time of the Day

Time of the Day

Traffi

c Vo

lum

e

SPEED CHARACTERISTICS The speed data for the approach was summarized and

analyzed:

0 10 20 30 40 50 60 70 800

50010001500200025003000350040004500

Speed Frequency Curve

southboundNorthbound

Speed (mph)

Freq

uenc

y

SPEED CHARACTERISTICS From the speed (OGIVE curve, estimate 85th percentile speed

by approach

5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 800%

20%

40%

60%

80%

100%

120%

Cumulative Frequency Curve (OGIVE)

NorthboundSouthbound

Speed

Cum

ulat

ive

%

TRAFFIC PROJECTION (YEAR 2015) Intersection Volumes

AM

PM

TRAFFIC PROJECTION (YEAR 2035) Using 6% traffic growth rate, the existing AM

and PM turning movement counts (TMC) to year 2035 were projected Future traffic = P(1+r)n

Where P = existing traffic r = traffic growth rate n = years of projection (2035 – 2015 = 20 years)

EXISTING CONDITION (YEAR 2015)LEVEL OF SERVICE ANALYSIS

As a whole, this intersection is efficient and has great conditions pertaining to traffic flow. The LOS is of the intersection is very

good, the lane approach LOS are A and B in the AM and PM hours. This is a very high Level of Service for an intersection. As

of today, there are no needs for any changes to the intersection. This intersections flow of traffic performs very well

with low traffic volume. AM PM

EXISTING CONDITION (YEAR 2015)LEVEL OF SERVICE ANALYSIS Given the previous data and analysis, there

is no need for any changes or improvements to the intersection.

All Level of Service ratings are at the A or B level, which is very good for an intersection.

YEAR 2035 WITH EXISTING GEOMETRY LEVEL OF SERVICE (**Utilize the existing lane geometrized, turning, movement

volumes, traffic characteristics, and signal timing data provided and by using traffic analysis Synchro Analysis.**)

AM improved in 2035

YEAR 2035 WITH EXISTING GEOMETRY LEVEL OF SERVICE PM improved in 2035

The Level of Service (LOS) is far less efficient in the year of 2035. Level of Service has changed from LOS of A or B at all intersections in 2015; to a LOS of C, D, E, and F in the year 2035 at the intersection. The increasing of the volume caused the LOS to lower and queuing to take place at the intersection.

All lanes except north bound through (LOS of A), were in need of improvements. All other lanes were under the LOS of C and need consideration for changes to improve the Level of Service to maintain a good traffic flow at the intersection.

YEAR 2035 WITH IMPROVED GEOMETRY LEVEL OF SERVICE AM improved with additional changes (final reconstruction of the intersection

for 2035)

YEAR 2035 WITH IMPROVED GEOMETRY LEVEL OF SERVICE Proposed changes made for the PM peak hour of traffic A Storage lane of 100

ft was added to the north bound right lane and 150 ft was added to south bound left lane for turning across traffic.

CRASH ANALYSISCrash data for the respective intersection

at 39th Ave N and Walter S. Davis Blvd was acquired from the city database.

There were a total of 238 crashes during this particular duration, resulting in an average of 119 crashes per year.

Although there numerous types of collisions, it is worth noting there were no pedestrian crashes.

CRASH ANALYSISThe most common types of crashes

areRear-end collisions with motor vehicles, at 18.49%,

Followed by backed-into collisions and right-turn collisions each at 12.61%

Left-turn and sideswipe collisions each at 11.76%.

SAFETY ANALYSIS 39th Ave N and Walter S. Davis Blvd is a relatively non-busy intersection

compared to others surrounding Tennessee State University. A very high number of crashes are occurring at these road segments. There

were a total number of 238 crashes over the two-year period, with crashes slightly increasing from Year 1 to Year 2.

Given that traffic at this intersection will greatly increase by 2035, several appropriate changes will need to be made to ensure safety for all traveling patrons. Some of these changes include intersection lane width, forming additional shared lanes, and providing additional turning signage. Feasibility and cost will be taken into consideration when creating a specific combination of changes to improve this intersection.

CONCLUSIONS AND RECOMMENDATIONS The data found for the intersection at the current time in 2015, gives a great Level of

Service (LOS) for the intersection. The Intersection had a Level of Service (LOS) of A and B for both AM and PM peak hours. All levels are above the Level of Service (LOS) of C, so there is no need for improvements of the intersection at this time in 2015.

The predicted 2035 values had many problems. The last prediction done was by changing the intersections geometry as a whole. This will

require major construction, but this is the only way to get an affect intersection in the year 2035. Two thru lanes and two left turning lanes were built for south bound on Walter S. Davis Blvd. Another change made was adding a storage right turning lane for the north bound of Walter S. Davis Blvd. The last change that was made to add an east bound lane on 39th street and leave the two left and right turns entering the intersection from 39th Ave.