November 1, 2014

Dr. Edward Mcmahon

Mr. Trevor Elliott

University of Tennessee at Chattanooga

615 McCallie Avenue

Chattanooga, TN 37403-2598

To whom it may concern,

The Road Design team is presenting a report concerning the proposed redesign of State Route 317

in the Collegedale area. This proposal includes the design plan and evaluation for the storm

drainage system for phase 2 of a 4 phase project, progress made thus far on the design, and the

groups future time line for completion. The team member’s skills and resumes are also included. If

you have any questions or comments regarding the project please contact me at (615) 542-0491.

Sincerely,

Jeremy Moody

Road Design Team Manager

Sponsor: TDOTTeam Members:Jeremy MoodyKyle PhillipsNikita HemnaniDaniel FussellTarek Azzouz

April 21, 2014

Road Design Storm Drainage Report

Executive Summary

This report was created to provide a final design and cost estimate for the design of the storm drainage

system for State Route 317 from the new connector at Interstate 75 Enterprise South Interchange and

extending for approximately 2.1 miles. The design of the storm drainage system will follow the

expansion and widening of the road per TDOT‘s request.

The design of the storm drainage system will include the inlet box locations, outlet box locations, and

piping system between the road and the outflow areas of the drainage area. The expanded road and

surrounding areas will be divided into separate drainage area’s to provide the area flow of water into

each inlet box. With the drainage areas and the estimated intensity values of the area, the flow of water

through the piping system can be calculated to estimate the pipe size required.

To design a new storm drainage system for this road will require that the existing outflow drainage

streams do not see an increase of flow due to the road or drainage system. This is to ensure that the

environment is affected as little as possible.

Table of ContentsExecutive Summary.....................................................................................................................................3

1) Introduction.........................................................................................................................................5

a) Problem Statement..........................................................................................................................5

i. Right of Way................................................................................................................................5

ii. Storm Drainage............................................................................................................................5

b) Project Mission and Goals...............................................................................................................6

c) Design Objectives............................................................................................................................7

d) Benefits to Client.............................................................................................................................7

2) Background..........................................................................................................................................7

1. Right of Way....................................................................................................................................7

2. Storm Drainage..............................................................................................................................10

3) Description of Design.........................................................................................................................13

a) Overall Description........................................................................................................................13

b) Description of Subsystems.............................................................................................................13

c) Detailed Description......................................................................................................................16

4) Detailed Cost Estimate.......................................................................................................................19

5) Conclusions and Recommendations..................................................................................................21

6) References.........................................................................................................................................22

7) Appendix............................................................................................................................................23

1) Introduction

a) Problem Statement

i. Right of Way

This design is being proposed to alleviate traffic demands on State Route 317 beginning at the new

connector from Interstate 75 Enterprise South Interchange and extending for approximately 2.1 miles.

This design is on Phase 2 of a 4 Phase project and Phase 2 encompasses Section 1 of a total of 5 sections.

The substandard two lane road currently being used has no shoulders or sidewalks which in effect limit

pedestrian traffic via bicycles and foot traffic. The route is predicted to surpass its level of service (LOS)

limit and needs to be widened to accommodate a heavier flow of traffic brought about by the expansion

of the McKee Foods Corporation as well as new residential developments that are in the planning

and/or construction phase. One of the busiest general aviation airports in Tennessee, the Collegedale

Municipal Airport, is also located on State Route 317. TDOT has mentioned that along with the widening

of the road a section at one end has an issue with deficient alignments and lane widths that prohibits 18

wheelers from using it safely due to limited sight distance caused by current design.

The new design proposed will incorporate curbs and gutters, 6’ shoulders for bicycle use, and sidewalks

on both sides of the route to accommodate pedestrian traffic. It will also widen the existing route to

either four 12’ traffic lanes with a continuous 12’ center turn lane, or four 12’ lanes with a 22’ raised

median with median breaks placed at appropriate locations.

ii. Storm Drainage

To allow for the expansion of the area surrounding state route 317 within phase 2 of the 4 phase

project, a new storm drainage design is required. The current storm drainage system that is in place is

designed to handle the drainage produced by the residential and commercial properties. The design will

include all aspects of the storm drainage including but not limited to detention/retention ponds, catch

basins, the curb and gutter system, storm drain inlets/outlets, ditches, all necessary piping, any pumps,

access holes, and water quality control facilities. The storm drainage system will be designed using a 10

year frequency and a maximum overflow of a 100 year frequency storm event to ensure that the storm

drain will be able to manage the flooding events that can occur. The design of the drainage system must

allow for the drainage of the newly designed 60’ wide four lane roadway that is 2.1 miles in length. The

storm drain system must be able to handle the water flow from surrounding drainage areas and

properly transfer the storm water to existing outlet locations. This will show possible features that will

benefit future designs and benefit the public’s needs.

b) Project Mission and Goals

The first mission for this project is to design a R.O.W that will sufficiently handle the deficient vertical

and horizontal alignments and design an adequate storm drain system that will handle the water runoff

from the new roadway.

The primary goal of the R.O.W design is to determine right of way (R.O.W) path that will minimally affect

the surrounding neighborhood and environment and increase the level of service of the road. In general,

this is accomplished by:

Determine the best path for R.O.W to not disturb current housing

Determine desired cut and fill

Identify construction equipment zones

Determine flow of traffic path during construction

The primary goal of storm drainage design is to limit the depth and spread of water flowing on the

roadway and the ponding at sag points so that it will not interfere with the passage of traffic during the

design frequency storm. In general, this is accomplished by:

Placing inlets at the locations and intervals necessary to control spread by intercepting flows

Providing storm drain pipes adequately sized to transport flows from the inlets to suitable outlet

locations

Determine appropriate drainage areas for the system

Determine newly designed roadway runoff

Determine adequate piping size to handle water runoff

Determine proper location for water inlets

Determine existing rainfall outlets

c) Design Objectives

There are two objectives for this project:

The first objective is to raise the L.O.S. of the road, and to give better accessibility to Mackee

foods corporation factory. The new road design should also be a low cost option, traffic flow not

inhibited, minimal construction time, and low impact on environment.

The second objective is to design a drainage system that supports the excess water flows from

the expansion of the new roadway, the surrounding drainage areas, and the future commercial

and business run off, and transfer this flow to the appropriate water outlets.

d) Benefits to Client

The benefits for the client, TDOT, will be a road construction plan that satisfies the design criteria,

enhanced local and regional accessibility, improved safety and operating conditions along the corridor,

increased traffic capacity, enhancement of future planned growth by local and/or regional land use

planning agencies, a storm drainage system that supports the newly designed 60’ wide roadway, as well

as the water flow that would occur from the population expansion within the area. This R.O.W design

will correct the deficient vertical and horizontal alignments and lane widths. This will allow the route to

better accommodate larger vehicles safely due to increased sight distance. The drainage system will

have less negative environmental impact and properly handle the water rainfall so that there aren’t any

negative impacts on the public.

2) Background

1. Right of Way

Road design is what has provided a thriving foundation for both global and local economies. Roads are

used on a daily basis for us to get from point A to point B. However, their practicality is much more

extensive than given credit for.

The first indications of a constructed road date back to around 4000 BC in modern day Iraq. This road

was constructed of stone and was the first of its kind. In the 1800s, road developers decided that it was

mandatory to include water in the mixture to allow for a smooth unified road surface. The modern style

pavement design as we know it today was developed by a blind man named John Metcalfe. He designed

his pavement out of three layers: large stones, excavated road material, and a layer of gravel. Shortly

after Metcalfe’s death, a pair of Scottish engineers named Thomas Telford and John McAdam developed

Metcalfe’s road design even further and created a raised center to allow water to drain to the outer

edges of the road. Also, they decided that broken stones allowed for better road strength and stability

while creating a smoother surface finish.

The objective of this project is to create a road the will fix the insufficient vertical and horizontal

alignments and lane widths throughout. This is to allow for safer transportation as well as increased

accessibility of goods and people along Apison Pike by allowing for increased sight distance.

To further explain and correctly define the project several key words are involved in the road design

process. Sag vertical curves, crest vertical curves, horizontal alignment, and lane width are all design

standards that govern every road that is built today.

Sag vertical curves are hills when viewed from the side are valleys. These types of curves are important

when designing for night time driving because the driver is limited to see what is visible in front of them

in their headlight beams, and the sag vertical curve cuts that short. An example of sag vertical curves can

be seen in Figure 1.

Figure 1: Picture of Sag Vertical Curve.

Crest vertical curves are simply hills that are convex upward. The main goal when designing for crest

vertical curves is stopping sight distance. Since the hill is typically a blind hill, the roadway must be

designed so that the driver will not hit any unforeseen obstructions in the road such as a stalled vehicle

or animal in the road.

Figure 2: Picture of Crest Vertical Curve.

Horizontal alignments of a roadway consist of straight sections of roadway connected by circular curves

to simply change direction of movement. The main factors in the design of horizontal curves are the

speed of the given roadway and the radius of the curve. If a roadway is designed at high speeds and a

tight radius, vehicles may be more prone to wrecking at the tight curvature. To avoid this, a bank would

be needed to be designed to keep vehicles on the roadway. For this specific project, the goal is to

eliminate any tight radii curves to help flow of traffic and to allow for the movement of transfer trucks

with increased visibility. Figure 3 shows an example of a horizontal alignment.

Figure 3: Picture of Horizontal Alignment.

The width of each individual lane effects functionality of the road as well as cost of building and

maintaining the road. The width of lanes typically falls into the 10’ to 12’ foot range with wider roads

being found primarily on high volume, high speed roads such as highways or interstates and where

restrictions on land are not a factor. For smaller volume roads that move primarily large trucks the 12’

lane would be used. Narrow lanes are cheaper to build and maintain but have a higher number of

vehicles that leave the roadway and higher quantity of head on collisions.

All of these aspects of roadway design have been considered in this project since one goal of this project

is to maximize truck sight distance and safety by eliminating as many vertical and horizontal curves as

possible and by maximizing lane widths.

All of these aspects of roadway design have been considered in this project since one goal of this project

is to maximize truck sight distance and safety by eliminating as many vertical and horizontal curves as

possible and by maximizing lane widths.

1.

2. Storm Drainage

Storm drainage systems for transportation facilities collect stormwater flowing within and along the

highway right-of-way and transfer it to a suitable discharge point. A storm drainage system collects

water either from the road using drainage inlets or from the surrounding drainage area using area

drains. An example of these can be seen in Figure 4 and 5 below.

Figure 4: Picture of a Drainage Road Inlet.

Figure 5: Picture of an Area Drain.

A proper highway drainage design will help to reduce many of the effects of an inadequate road

drainage system, including:

Water flowing from the roadway onto adjacent properties

Water ponding behind the roadway curbs

Hazards and delay to traffic caused by excessive ponding in sag points or excessive spread on

the roadway.

Weakening of the base and subgrade caused by frequent long-duration ponding of water

The purpose of any storm water design should be to make every reasonable effort to promote the safety

of the traveling public by providing adequate drainage performance in the most cost-effective way. The

storm drainage system for a roadway project may be organized based upon outlet points for each

individual segment. Each segment of the roadway drainage system will have an outlet to either a side

ditch or a cross drain. A picture of a storm drain outlet can be seen in Figure 6 below.

Figure 6: Picture of Storm drain Outlet.

A proposed storm drainage system will intercept runoff from off-site drainage areas. The drainage areas

and time of concentration for these off-site areas would be listed in the inlet or other computations.

3) Description of Design

a) Overall Description

The road design process can be broken down into three main systems. The three systems that make up

the design process are drainage, pavement design, and alignment. These three are identified because in

every road design these milestones are necessary to complete the overall project . These systems can be

broken down into their own individual subsystems, with each subsystem containing its own components

which are commonly categorized by function, and objectives needed to complete each individual

process. A breakdown of the primary function, basic functions, and the sub functions in the function

node tree can be seen in the Appendix.

A storm drainage system can vary from one jobsite to another. These variances will include different

inlet locations, different outlet locations, different size piping, different water retention devices, and

different culvert slope gradients. These differences are site specific and will be designed before

construction begins but every storm drainage system is designed the in the same manor. The slope of

the road provides an outward sloping gradient from the peak in the center of the lane. This slope will

cause the water rainfall to directed to the curb and gutter system. The curb and gutter system follows

along the entire length of the road and the road is designed to be either at a positive or negative

gradient. The water rainfall will follow along the curb and gutter system along the road until it reaches a

culvert inlet box location. The culvert inlet box will act as a drain for the road. The culvert inlet will be

connected to underground storm drainage piping which is designed on an in ground gradient which

allows the water from the inlet box to travel underground to a culvert outlet box. The outlet box directs

the storm rainfall to existing water outflow areas to either streams or rivers.

b) Description of Subsystems

i) Drainage

The overall drainage system can be separated into two subsystems. These subsystems are generally

called the Major and Minor systems (the Minor system is sometimes referred to as the convenience

system). Historically the Minor system was the only subsystem given attention to in the design process,

with the Major system being overlooked in most cases. Today’s road design projects take into

consideration both Minor and Major systems. As weather patterns become more turbulent and surface

runoff from urban sprawl increases the Major system is becoming increasingly important to the overall

design of any urban roadway project.

Drainage minor System: The Minor system is typically designed to carry runoff from 10 year

frequency storm events and its components make up the majority of what people consider the drainage

system. These components are put into three distinct categories which are dictated by the function of

each component. The three function categories are collection, conveyance, and discharge.

The collection of stormwater runoff from the roadway surface and ROW is a function of the Minor

stormwater drainage system, and is manifested within a road design project in the form of: median and

roadside ditches, gutters, and drainage inlets. The ditches are located and shaped to avoid being a

traffic hazard, and can either have Channel linings to control erosion or vegetative linings when design

velocities permit. The gutters intercept runoff primarily from the roadway surface and, in some

instances, ROW at which point it is carried alongside the roadway shoulder to an adequate storm drain

inlet. Usually curbs are installed with gutters to either help avoid erosion of fill slopes, or where either

ROW or topographical conditions prohibit roadside ditches. The drainage inlets are receptors for the

surface water collected from ditches and/or gutters, and serve as an entrance to the storm drains.

Drainage inlets take on many forms, and when located alongside the roadway shoulders they are

designed in such a way as to limit the spread of surface water onto travel lanes.

The conveyance of stormwater begins when the runoff reaches the main storm drainage system, at

which point it is transported along and through the ROW to the discharge point. The main storm

drainage system begins with storm drains which receive runoff from inlets and convey it to a channel,

body of water, or other piped system; be it closed conduit or open channel. The piping system is

comprised not only of pipes, but also contains access holes, junction boxes, and inlets. These aspects of

the piping system are located at intersections of two or more storm drains, or when there is a change in

pipe size or alignment and are generally dictated by critical design parameters. On occasion, when

gravity drainage is not feasible due to geographic or economic factors a stormwater pump station may

be used during the conveyance process.

Quantity and quality of stormwater is what dictates the discharge function of the Minor system. By

including detention/retention ponds the quantity of runoff discharged into receiving waters can be

controlled. The quality of the runoff can be controlled by: extended detention ponds, wet ponds,

infiltration trenches, infiltration basins, porous pavements, sand filters, water quality inlets, vegetative

practices, erosion control practices, and wetlands. They can help to impede, and/or eliminate:

suspended solids, heavy metals, excessive nutrients, and organics into receiving waters.

Major System: The Major system provides overland relief of stormwater flows that would exceed

those of the Minor system and are normally designed to have a capacity of a 100 year frequency storm

event.

The main function involved with the Major system is flood water relief. It is typically provided by

streets, surface swales, ditches, streams, and/or other flow conduits which provide a relief mechanism

and flow path for flood waters.

The major system acts as a safety device for the minor system. The minor system is only equipped to

handle a 10 year frequency storm so if a storm comes that would exceed the minor systems capabilities

then the major system would divert the water in a different manor to ensure flooding and ponding are

minimalized.

ii. Pavement Design

The pavement for the specified road will be designed to transfer the loads of vehicles to the sub-grade

while ensuring that passengers’ ride quality is nothing less than smooth. The designed pavement will be

structurally strong so that the pavement will transfer forces to the ground as well as keeping the design

life as long as possible and minimizing post construction maintenance costs.

iii. Alignment

The road design we have chosen eliminates most drastic horizontal and vertical alignments. One of the

main concerns for the project was to ensure that truck drivers from McKee foods are able to drive the

road safely. For example, one curve on the existing road had improper vertical as well as horizontal

alignments leading drivers into a blind right turn atop a hill. This will be fixed with the reconstruction of

the road to the specified design.

c) Detailed Description

The storm drainage system for Apison pike is made up of catch basins, area drains, and the piping

system. The catch basins are limited to no more than 400’ apart to prevent sagging in the piping system

and create a point where the pipe can change direction if desired. The pipe is also limited to the

straightest path to allow for clear flow through the system. With these constraints It was estimated that

between 100 to 140 catch basins will be required along the entire 2 mile stretch of road expansion.

Along with these catch basins the pipe required to move the flow of water will vary as the lengths of

pipe get longer and there are no outflow areas to disperse the water. The piping system will start out at

18” circular reinforced concrete pipe (CRCP) and steadily increase depending on the flow of water.

Figure 7 below shows the entire length of road with some of the drainage areas specified.

Figure 7: Picture of Entire Road.

Figure 8 below shows a section of the road where the drainage area has been delineated and drawn

with the catch basin locations. Between catch basin 16 and 17 it shows the piping system at 42” CRCP,

this is because all the water flowing before this location is all being carried by the piping system and

there is a headwall with outflow drain roughly at catch basin 31. This piping system is not only carrying

all the water off the road and surrounding area but also all the water uphill from it. As the flow of water

gets larger the pipe size will get larger.

Drainage Area

Figure 8: Picture of Section of Road with Drainage Areas.

Based on the drainage areas and where the outflow locations for the drainage system are, the estimated

total pipe can be seen in Table 1 below.

Table 1: Pipe Sizes and Total Lengths.

Pipe Diameter, in's Units, ft Quantity, ft

18 LF 110524 LF 42236 LF 042 LF 150854 LF 75860 LF 468

The outflow area for the piping system will be designed to direct the flow of water to the existing

streams or rivers. This is done by placing an endwall or a headwall at the end of the piping system that

will allow the water in the pipe to be discharged into the local discharge areas. Figure 9 below shows the

headwall near catch basin 31.

Catch Basin

Figure 9: Picture of Endwall or Headwall Outflow Area.

The outflow area must also not discharge the water at a greater velocity than the velocity of water

before construction. This is done to prevent erosion of soil and stabilization and to not affect any wildlife

downstream. To control the velocity of water along the piping system manholes and junction boxes can

be used to drop the elevation of pipe down to a lower elevation to stop the constant velocity along the

pipe. The more water the is introduced to the piping system the greater the flow so more than one

junction box or manhole may be needed along the entire length of the road.

4) Detailed Cost Estimate

The cost analysis for the storm water portion of State Route 317 (Apison Pike) consists of two main

sections: the “Design to Date” Estimate, and the “Total Projected Design” Estimate. Each table will be

composed of these two sections to show both the estimated cost of what has been actually designed to

date, and the estimated cost of the entire “projected” design.

Endwall

Precast concrete components were chosen to be used for the entirety of the project for consistency and

durability. Table 2 below lists the pipe, by size (diameter), to be used within the project.

Table 2: Pipe Sizes and Associated Costs.

Pipe Diameter,

in's

Units, ft

Quantity, ft

Unit Price (per inch

diameter per lineal foot)

ExtensionQuantity,

ft

Unit Price (per inch

diameter per lineal foot)

Extension

18 LF 1105 $5.00 $99,450.00 8000 $5.00 $720,000.0024 LF 422 $5.00 $50,640.00 1200 $5.00 $144,000.0036 LF 0 $5.00 $0.00 700 $5.00 $126,000.0042 LF 1508 $5.00 $316,680.00 1400 $5.00 $294,000.0054 LF 758 $5.00 $204,660.00 800 $5.00 $216,000.0060 LF 468 $5.00 $140,400.00 500 $5.00 $150,000.00

$811,830.00 $1,650,000

Circular Precast Concrete Storm Drain

Total Projected Cost

Designed to Date Estimated Cost of Complete Design

Cost of Completed Design

The Unit Price (per inch diameter per lineal foot) used in the table was found on the “Urban Drainage

and Flood Control” of Colorado website. It uses data compiled between the years of 2005-2009, and

was developed in 2010 to be used as a cost estimator for master planning. The program is excel based

and gives the user the option to include current, CCI (Construction Cost Index) and Inflation, rates to

adjust the costs of components used within any given project. The unit costs are complete-in-place and

include all associated costs for excavation, bedding, placement, and backfill. These prices will inevitably

be higher than the actual price due to some of the complete-in-place processes happening during, and

for, other phases of the Road Project as a whole.

The component costs were obtained in a similar fashion as the Unit Prices for the pipe. After adjusting

for the CCI and Inflation rates using “Urban Drainage and Flood Control” software the worst case

scenario was used to estimate each component. Table 3 below shows the estimated component list and

associated cost.

Table 3: Component List and Associated Costs.

Component UnitItem Description ft. Quantity Unit Price Extension Quantity Unit Price Extension

Catch Basin (Area Drain) SF 2 $7,500 $15,000 5 $7,500 $37,500.00Catch Basin (Single Grate Inlet) SF 29 $6,000 $174,000 120 $6,000 $720,000.00

Junction Box SF 5 $4,500 $22,500 15 $4,500 $67,500.00Manhole (6' diameter) each 1 $10,500 $10,500 7 $10,500 $73,500.00

Headwall (60" double pipe) $3,500 $0 $3,500 $0.00Wingwall (11' x 11') $5,000 $0 $5,000 $0.00

Curb and Gutter LF 3800 $50.00 $190,000 10,000 $50.00 $500,000.00

$412,000 $1,398,500.00

Component Price EstimateDesign to Date Estimate Projected Design Estimate

Total Projected Component

Estimate

Projected Design to Date Estimate

The cost estimate of the project is located in Table 4 below and as stated above is based on the worst

case scenario due to lack of design data. The “Project to Date” cost estimate will be much closer to the

actual cost than the “Projected Total” due to dimensional assumptions made during Cost Analysis.

Table 4: Total Cost Estimate.

Project to Date Projected TotalUnit Cost Cost

Pipe Total $811,830.00 $1,650,000Component Total $412,000.00 $1,398,500

Total Estimated Cost $1,223,830.00 $3,048,500

Cost Estimate of Project

5) Conclusions and Recommendations

We started this year off with one project and one goal. We were to design a road that would alleviate

traffic demands on state route 317. While working on this project the team was redirected towards

designing the drainage alone for this roadway, because we were led to believe that too much

information had been given to us regarding the roadway design. We began this design of drainage at the

beginning of the fall semester, and have been working consistently to accomplish this. With the amount

of time our group has had to design this system, we will not have the complete drainage system for the

full length of the road within our project area. The Drainage system of this roadway has been designed

up until the catch basin 17 but plan on design up to catch basin 31 this week.

One recommendation that we have in performing this project would be a longer time period for our

group to focus on simply the drainage design of our assigned road. The fact that we had to switch

projects mid-year due to confusion within the project as a whole, has put us back and limited the extent

we can dig into this project.

Also, we feel that easier, more fluid access to the TDOT Microstation program would have substantially

made this project better. Allowing us to receive and give information more easily, as well as receive help

from users who have experience using the Microstation program.

6) References

Transportation Planning Report by Tennessee Department of Transportation, Project Planning Division.

http://inventors.about.com/od/rstartinventions/a/History-Of-Roads.htm

http://www.triplenine.org/articles/roadbuilding.asp

http://www.tdot.state.tn.us/chief_engineer/assistant_engineer_design/design/DesGuide.htm

http://www.tdot.state.tn.us/Chief_Engineer/assistant_engineer_design/design/DrainManpdf/Chapter%203.pdf

http://www.tdot.state.tn.us/Chief_Engineer/assistant_engineer_design/design/DrainManpdf/Chapter%204.pdf

7) Appendix

Storm Drainage Function Tree