Introduction
The section under analysis covers the distance from Milton Road in the West Butler Avenue to Ponderosa Parkway in the East Butler Avenue. This is a multilane highway with 4 lanes covering a distance of three miles. The avenue is both divided at some section and undivided in others with numerous access points. The traffic projections over the next six years are calculated using an estimated 5 percent growth rate in hourly traffic volume. The report also analyses whether the 4-lane highway will accommodate the projected traffic in 2020. Data collection was done through online research and physical observation of the Butler Avenue from Milton Road to Ponderosa Parkway.
Data Collection
Data was collected through online research, where traffic volume data was downloaded from The City of Flagstaff. The data retrieved from City of Flagstaff website was collected in 2012, from different sections of the avenue. The report uses the average of all the sections covered in the 2012 Traffic count file from the City’s website.
Data retrieved from The City of Flagstaff
The total number of hours the cars were counted was 672 minutes and the total average volume was 133,106. The shoulder width was 6 feet, lane width was 12 feet, while the number of access points were 12. The calculated average access point density is 0.4. This means that for every 0.4 KM traveled there is an access point on the road.
Analysis
The data indicates that the highway is congested during peak hours. To analyze the data, the following formulas will be used.
The peak volume vp=VPHF*N*fH*fp ..eqn1 (Saxena, 44).
Where V= to number of cars per hour
PHF= peak hourly flow
N=number of lanes =4
fH=Heavy vehicle adjustment factor =6
fp=passenger car adjustment factor=2
V =133,10614= 9507.6
The avenue carries an average of 9507.6 in 48 minutes during peak hours.
In the next six years, the traffic in 48 minute during peak hours will be 11556.5 considering a 5 percent growth in hourly rate.
Butler Avenue’s current service volume is
SV= 9507.6*4860 =7606 =vp
Peak hourly volume is equal to the number of cars served in one peak hour, which is equal to service volume and V is the peak volume. Therefore,
PHF=9507.6*100*1004*7606*6*2=260.4
In 2020, V will be equal to 11,556.5
vp will be 11,556.5*4860 =9245
The Number of lanes N needed to handle such traffic is given by rearranging eqn1 above
N=11556.5*100*100260*9245*6*2=4.0
Therefore, the number of lanes required for efficient flow of traffic in 2020 is four lanes.
Discussion
Conclusion and Recommendation
In conclusion, the Butler Avenue is safe to handle traffic in the coming six years through to 2020. The report recommends the avenue to be maintained with projections beyond 2020 made over the next six years.
References
Saxena, Meeta. “Comparison of Various Methods to Compute Access Density and Proposing a Weighted Methodology.” Scholar Commons. (2010): 41-50. Web.
