Estimating the Life-Cycle Cost of Intersection Designs (2016)

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NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4 – Case Studies Page 66 CHAPTER 4 CASE STUDIES As part of the LCCET validation process, the team prepared illustrative case studies to demonstrate the tool’s value to prospective users and to facilitate implementation. Through the agency coordination process during Phase I of the project, the team identified those agencies that had interest in participating and had projects suitable for including as a case study. Through this process the team identified six case studies that would show the functionality and effectiveness of the tool. In addition, the team created one hypothetical case study that would further demonstrate some of the other attributes of the tool, such as the ability to account for emissions. Table 4-1 summarizes the case studies that were developed as part of this project task: Table 4-1: Summary of Case Studies Case Study Location/Agency Base Case Alternatives 1 Eagle Road/State Street Ada County Highway District Eagle, Idaho Existing Signalized Intersection • Multilane Roundabout • Enhanced Signal 2 Powell Butte Hwy/Neff Road Deschutes County Bend, Oregon Existing Two-Way Stop Controlled • Two Offset Intersections • Single-lane Roundabout 3 Jackson School Road/Scotch Church Road/Meek Road Washington County Hillsboro, Oregon Existing Offset Side- street Stop Controlled • Single-lane Roundabout • Signalized Intersection 4 SR-123 (San Pablo Ave)/Bancroft Way Caltrans Alameda County, California Existing Two-Way Stop Controlled • Signalized Intersection 5 US 40/MD 213 Maryland State Highway Administration Cecil County, Maryland Existing Signalized Intersection • Median U-Turn Intersection 6 Hypothetical Example All-Way Stop Controlled • Signalized Intersection • Single-lane Roundabout Appendix C contains a summary of the LCCET worksheets for each of the case studies to correspond with the material presented throughout this chapter. 4.1. CASE STUDY 1: EAGLE ROAD/STATE STREET INTERSECTION Case Study 1 was created based on data obtained from an intersection alternatives evaluation conducted for the Ada County Highway District (ACHD) in December 2013 at the Eagle Road/State Street intersection in Eagle, Idaho. The purpose for the Eagle/State Intersection Concept Study was to develop a prioritized implementation plan identifying a preferred configuration and concept design for the Eagle Road/State Street intersection. For this concept study, a consultant was hired by the county to conduct the traffic analysis and to

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4–Case Studies Page 67 provide perspective on the various transportation alternatives. The following two intersection alternatives were considered for this case study. • Alternative 0: Base case (existing signalized intersection) • Alternative 1: Roundabout (construction of a multilane roundabout) • Alternative 2: Enhanced signalized intersection (expansion of the intersection as a signalized intersection) Figures 4-1 and 4-2 illustrate conceptual layouts of the two alternatives that were evaluated. Figure 4-1: Alternative 1 Roundabout Figure 4-2: Alternative 2 Enhanced Signal Alternative 1, shown in Figure 4-1, evaluated a multilane roundabout at the Eagle Road/State Street intersection, which was assumed to have two entry lanes on all intersection legs, two exit lanes on the Eagle Road legs, and single exit lanes on the State Street legs. Alternative 2, shown in Figure 4-2, evaluated an expanded signal alternative that maintains the existing signalized intersection control at the Eagle Road/State Street intersection, but adds lanes to the critical movements at the intersection: an additional northbound through lane, westbound left-turn lane, and southbound right-turn lane. Case Study 1 evaluated both alternatives using the LCCET. A majority of the information included in the tool for this alternative comparison was obtained from the concept study conducted for the county. However, some information that may normally be included in the tool was not available as part of the Concept Study. Therefore, assumptions were made in four key areas to complete the evaluation for the purposes of this example. • A base year analysis of the alternatives is required to provide a common comparison point between potential future alternatives. For this case

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4 – Case Studies Page 68 study, a base year analysis of alternatives was not available from the state agency. Therefore, assumptions were made for this case study evaluation to provide a consistent base scenario from which the signalized and roundabout alternatives could be compared. • A detailed safety evaluation was not conducted as part of this case study. However, available crash data were entered into the tool, and certain assumptions were made as to the safety effects of various treatments for this case study. The Highway Safety Manual and other resources provide the ability for analysts to determine this information. • The intersection alternatives study did not consider pedestrian delay, bicycle delay, transit delay, reliability, or emissions. As such, these costs were omitted from the case study evaluation. • The ACHD concept study did not provide detailed demand profiles or cost parameters. As such, the evaluation relies on default values contained in the tool. Table 4-2 shows the basic characteristics that were used in the evaluation.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4–Case Studies Page 69 Table 4-2: Case Study Information Summary Alternative: Base Case Roundabout Enhanced Signal Base Analysis Year 2014 Future Analysis Year 2035 Average Annual Daily Traffic (veh/d) Base 38,000 Future 67,000 Total Entering Volume (Base) (veh/h) AM 1,553 PM 2,117 Midday 2,164 Total Entering Volume (Future) (veh/h) AM 2,671 PM 3,535 Midday 3,484 Annual Trucks Base 2% Future 4% Transit/Bicycles/Pedestrians Not considered Delay (Base) (s/veh) AM 25 5 25 PM 27 30 27 Midday 26 28 26 Delay (Future) (s/veh) AM 43 11 77 PM 93 49 77 Midday 93 45 72 Base Year Safety Performance PDO Crashes 5 7 5 Injury Crashes 2 1 2 Fatal Crashes 0 0 0 Future Year Safety Performance PDO Crashes 10 11 9 Injury Crashes 4 1 4 Fatal Crashes 0 0 0 Planning/Engineering Costs $0 $622,819 $687,714 Right-of-Way Costs $0 $811,000 $474,554 Construction Costs $0 $3,111,000 $3,438,572 Net Present Value $131,724,932 $76,412,191 $131,099,984 Benefits/Costs n/a 13.03 1.14 Figure 4-3 illustrates the graphical results of the intersection alternative analysis.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4 – Case Studies Page 70 Figure 4-3: Graphical Output from Intersection Alternative Analysis This life-cycle cost evaluation shows that the roundabout alternative results in the least cost in terms of net present value. Interestingly, the enhanced signalized intersection alternative results in relatively small savings through the horizon year due to an increased likelihood of crashes and modest savings in delay. 4.2. CASE STUDY 2: POWELL BUTTE HIGHWAY/NEFF ROAD Case Study 2 was developed based on the Intersection Alternatives Review conducted at the Powell Butte Highway/Neff Road intersection in Deschutes County, Oregon. Based on the increasing number of crashes at this intersection, county staff were interested in identifying intersection safety improvements. The county has identified this intersection as a high priority location both in the County Transportation System Plan and in the Capital Improvement Plan. Figure 4-4 illustrates the existing intersection layout and traffic control.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4–Case Studies Page 71 Figure 4-4: Existing Powell Butte Highway/Neff Road Intersection East-west traffic at the intersection is controlled by stop signs, with uncontrolled north-south movements on the Powell Butte Highway. The county has previously implemented low-cost treatments to improve driver visibility at the rural, high-speed intersection, such as an overhead flashing beacon and Intersection Ahead signs with LED lights on the sign border that flash as motorists approach the intersection. However, based on the severity and types of crashes at this location, the county investigated more substantial intersection improvements. This case study considered the following intersection alternatives for this project location: • Alternative 0: Base case (existing unsignalized intersection) • Alternative 1: Roundabout (construction of a single-lane roundabout) • Alternative 2: Offset T-intersection (with two-way stop-control) Figures 4-5 and 4-6 illustrate the intersection alternatives that were evaluated.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4 – Case Studies Page 72 Figure 4-5: Alternative 1 - Roundabout Concept Alternative 1, shown in Figure 4-5, illustrates a single-lane roundabout concept that was considered. The roundabout includes an inscribed circle diameter of 160 feet and maintains all turning movements while minimizing the number of conflict points. The reduction in speeds on the approaches and removal of higher-severity head-on and angle crashes also reduces the crash severity. Figure 4-6: Alternative 2 - Offset T-Intersection Concept

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4–Case Studies Page 73 Alternative 2, shown in Figure 4-6, evaluated the intersection as two offset “T” intersections, which separates movements and reduces the number of conflict points from 32 to 22. This concept includes left-turn lanes and a median on Powell Butte Highway between the offset intersections. The Intersection Alternative Review did not include an analysis of existing conditions, meaning base case alternative information was not available from Deschutes County for this case study. To use the LCCET, a base year analysis of the alternatives is required to provide a common comparison point between potential future alternatives. Therefore, several assumptions were made for this case study evaluation to provide a consistent base scenario from which the signalized and roundabout alternatives could be compared. 4.2.1. DETERMINING TOTAL ENTERING VOLUME AND DELAY AT OFFSET INTERSECTIONS The calculation of total entering volume (TEV) and delay at traditional intersections is straightforward. However, the same calculation at offset intersections requires additional extrapolation of results by the analyst. Such extrapolations required within this case study are shown as an example. The concept for these calculations are shown in Figure 4-7.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4 – Case Studies Page 74 Figure 4-7: Offset T-Intersection Concept – TEV and Delay Calculations In general, TEV is calculated by adding all volume entering the intersection system, being careful not to double count vehicles. The method shown for calculating delay is a simplified approach that considers only control delay incurred at the intersections. Modified approaches are possible that would more completely account for running time between the intersections due to the spacing that is introduced by this alternative (such as that illustrated in Case Study 5). Table 4-3 shows the basic characteristics used in the evaluation. TEV: Add all turning movements. Exclude interior movements shown in red from TEV. Delay: Calculate total control delay within each circle. Divide sum of both circles by TEV for the entire intersection system.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4–Case Studies Page 75 Table 4-3: Case Study Information Summary Alternative: Base Case Two Offset Intersections Roundabout Base Analysis Year 2014 Future Analysis Year 2030 Average Annual Daily Traffic (veh/d) Base 6,470 Future 9,980 Total Entering Volume (Base) (veh/h) AM 511 PM 647 Midday n/a Total Entering Volume (Future) (veh/h) AM 855 PM 998 Midday n/a Annual Trucks Base 23% Future 23% Transit/Bicycles/Pedestrians n/a Delay (Base) (s/veh) AM 5.9 5.6 2.8 PM 4.4 4.2 3.5 Midday n/a n/a n/a Delay (Future) (s/veh) AM 12.4 7.0 5.8 PM 8.1 5.7 6.5 Midday n/a n/a n/a Base Year Safety Performance PDO Crashes 1.1 1.2 0.5 Injury Crashes 0.9 0.7 0.1 Fatal Crashes 0 0 0 Future Year Safety Performance PDO Crashes 1.1 1.2 0.5 Injury Crashes 0.9 0.7 0.1 Fatal Crashes 0 0 0 Planning/Engineering Costs $0 $504,000 $474,000 Right-of-Way Costs $0 $363,000 $139,000 Construction Costs $0 $2,015,000 $1,896,000 Net Present Value $3,526,429 $5,680,677 $3,667,749 Benefits/Costs n/a 0.26 0.94 Figure 4-7 illustrates the graphical results of the intersection alternative analysis.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4 – Case Studies Page 76 Figure 4-7: Graphical Output from Intersection Alternative Analysis This life-cycle cost evaluation shows that the roundabout alternative results in a lower cost than the two offset intersections, in terms of net present value. The roundabout alternative is expected to have a higher cost than the existing base alternative by approximately $140,000. However, due to other issues (horizontal and vertical curves that limit sight distance) the base case was not a viable option, and the county decided to move forward with the rural roundabout. 4.3. CASE STUDY 3: JACKSON SCHOOL ROAD/SCOTCH CHURCH ROAD/MEEK ROAD Case Study 3 was developed based on an Intersection Improvement Study conducted at the two T-intersections of Scotch Church Road and Meek Road along Jackson School Road in Washington County, Oregon. These intersections have experienced continued growth in traffic volumes which has created constrained traffic operations and increased safety concerns. Jackson School Road is a two-lane arterial running north-south. Scotch Church Road and Meek Road are two-lane roads running east-west that form T- intersections with Jackson School Road. Scotch Church Road forms the west leg of a T-intersection with Jackson School Road. Approximately 300 feet south of Scotch Church Road, Meek Road forms the east leg of a T-intersection with Jackson School Road. The intersections are controlled with stop signs on the eastbound and westbound approaches of Scotch Church Road and Meek Road, respectively. Scotch Church Road is expected to primarily see an increase in

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4–Case Studies Page 77 commuter traffic and Meek Road is expected to experience additional traffic from adjacent industrial developments. Figure 4-8 illustrates a schematic of the existing offset T-intersections. Figure 4-8: Existing Base Alternative Configuration The improvements being considered at this location include combining the two offset T-intersections into a single four-legged intersection by realigning Scotch Church Road or Meek Road, and installing a traffic signal or roundabout at the new intersection location. This case study considered the following intersection alternatives for this project location: • Alternative 0: Base case (existing offset T-intersections) • Alternative 1: Roundabout (construction of a single-lane roundabout) • Alternative 2: Signalized intersection Figure 4-9 illustrates a schematic of the realignment and location of the proposed improvements. Figure 4-9 illustrates the lane configurations considered for the roundabout and traffic signal alternatives. Figure 4-9: Alternative Realignment Configuration

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4 – Case Studies Page 78 Figure 4-10: Alternative Traffic Control and Lane Configurations Alternative 1 includes a roundabout with two lanes at both the northbound and southbound entries on Jackson School Road. The eastbound approach on Scotch Church Road includes a shared left-turn and through lane and a right-turn lane, while the westbound approach of Meek Road includes a shared left-through- right lane and a dedicated right-turn lane. Alternative 2 includes a traffic signal at the realigned intersection location. For this alternative, there are two through lanes in each direction on Jackson School Road, a dedicated left-turn lane, and a shared right-turn lane in the northbound and southbound directions. The eastbound approach includes a left-turn lane and a shared through/right-turn lane. The westbound approach includes a left- turn lane, a through lane, and two dedicated right-turn lanes. Protected left-turn phasing was assumed on all approaches. For this case study, base case alternative information was not available from the county. To use the LCCET, a base year analysis of the alternatives is required to provide a common comparison point between potential future alternatives. Therefore, several assumptions were made for the purposes of this case study evaluation to provide a consistent base scenario from which the signalized and roundabout alternatives could be compared. Table 4-4 shows the basic characteristics that were used in the evaluation.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4–Case Studies Page 79 Table 4-4 Case Study Information Summary Alternative: Base Case Roundabout Signal Base Analysis Year 2013 Future Analysis Year 2035 Average Annual Daily Traffic (veh/d) Base 13,750 Future 20,167 Total Entering Volume (Base) (veh/h) AM 1,250 PM 1,500 Midday n/a Total Entering Volume (Future) (veh/h) AM 2,000 PM 2,200 Midday n/a Annual Trucks Base 3% Future 4% Transit/Bicycles/Pedestrians n/a Delay (Base) (s/veh) AM 4.8 10.0 15.0 PM 3.3 10.01 15.0 Midday n/a n/a n/a Delay (Future) (s/veh) AM 143.2 17.5 27.2 PM 282.3 15.6 29.9 Midday n/a n/a n/a Base Safety Performance PDO Crashes 7.6 5.1 7.0 Injury Crashes 5.1 1.1 4.9 Fatal Crashes 0 0 0 Future Safety Performance PDO Crashes 7.6 5.12 7.0 Injury Crashes 5.1 1.1 4.9 Fatal Crashes 0 0 0 Planning/Engineering Costs n/a n/a n/a Right-of-Way Costs n/a n/a n/a Construction Costs n/a n/a n/a Net Present Value $20,841,265 $6,890,424 $19,285,681 Benefits/Costs Estimated capital costs not included in analysis 1Estimated existing delay for the alternatives. 2Assumed crashes are average per year through the horizon year (i.e., same in base and future years). Figure 4-11 illustrates the graphical results of the intersection alternative analysis.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4 – Case Studies Page 80 Figure 4-11: Graphical Output from Intersection Alternative Analysis As shown above, the life-cycle cost evaluation showed that the roundabout alternative results in a lower cost than the signalized intersection in terms of net present value. This is primarily due to the safety cost parameter that was used in the comparison, as shown graphically in Figure 4-11. 4.4. CASE STUDY 4: SR-123 (SAN PABLO AVE)/BANCROFT WAY Case Study 4 at the SR-123 (San Pablo Avenue)/Bancroft Way intersection is developed based on a proposal prepared by the Caltrans Office of Safety in Alameda County, California. The proposal identifies the need to install a traffic signal at the SR-123/Bancroft Way intersection to reduce the number and severity of broadside crashes and crashes between motorists and pedestrians. SR 123 is currently a north-south divided highway with left-turn lanes in both directions and two-way stop control on the east-west approaches of Bancroft Way. During the five-year period of 2007 to 2011, there were 20 crashes recorded at this intersection, nine of which were angle crashes. In addition, this intersection meets traffic signal warrants based on the pedestrian volumes.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4–Case Studies Page 81 The proposed traffic signal is expected to address the broadside crashes at this intersection and enhance the safety of pedestrians and bicycles by increasing the right-of-way control at the intersection. Based on this information, Case Study 4 considered the following intersection alternatives for this project location: • Alternative 0: Base case (existing unsignalized intersection) • Alternative 1: Signalized intersection This case study shows an example of an evaluation that considers only capital costs and safety benefits. Figure 4-12 illustrates an aerial view of the existing intersection location. Figure 4-12: Aerial View of SR-123/Bancroft Way Intersection Based on the proposal for this safety improvement, Case Study 4 included an evaluation of the safety characteristics, as shown in Table 4-5.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4 – Case Studies Page 82 Table 4-5: Case Study Information Summary – Safety Evaluation Alternative: Base Case Signal Base Analysis Year 2014 Future Analysis Year 2029 Base Year Safety Performance PDO Crashes 1.6 1.3 Injury Crashes 2.4 1.9 Fatal Crashes 0 0 Future Year Safety Performance PDO Crashes 1.6 1.31 Injury Crashes 2.4 1.9 Fatal Crashes 0 0 Planning/Engineering Costs n/a n/a Right-of-Way Costs n/a $70,000 Construction Costs n/a $550,000 Net Present Value $6,569,325 $4,762,229 Benefits/Costs n/a 3.91 1Assumed crashes are average per year through the horizon year (i.e., same in base and future years). Figure 4-13 illustrates the graphical results of the intersection alternative analysis.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4–Case Studies Page 83 Figure 4-13: Graphical Output from Intersection Alternative Analysis As shown above, the life-cycle cost evaluation showed that the signalized alternative would cost nearly $2 million less than the existing base alternative over the life of the intersection. This is primarily due to the safety cost parameter that was used in the comparison, as shown graphically in Exhibit 4-18. 4.5. CASE STUDY 5: US 40/MD 213 Case Study 5 is based on the conceptual design and analysis conducted for Maryland State Highway Administration (SHA) at the US 40/MD 213 intersection in Elkton, Maryland. Based on the need to relieve congestion and improve intersection safety, the conceptual design at this intersection includes a median U-turn intersection. The intersection of US 40/MD 213 is routinely identified as a Candidate Safety Improvement Location by SHA and experienced a substantial number of crashes during the three-year period of 2009 to 2011. One of the recommended improvements for the intersection is the median U-turn design, which would redirect all left turns to make U-turns on US 40 to either the east or west of the

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4 – Case Studies Page 84 main intersection. Based on this information, Case Study 5 considered the following intersection alternatives for this project location: • Alternative 0: Base case (existing offset T-intersections) • Alternative 1: Median U-turn intersection Figure 4-14 displays a schematic of an example of a median U-turn. As noted in the exhibit, left turns at a median U-turn are prohibited at the main intersection and are instead made indirectly. From the major street (US 40 in this case), a left turn would be made by proceeding through the main intersection, making a U- turn at a signalized crossover beyond the main intersection, and then returning to the main intersection and making a right turn. From the minor street (MD 213), a left turn would be made by making a right turn at the main intersection, proceeding to the signalized crossover to make a U-turn, and then proceeding back through the main intersection on the major street in the desired direction of travel. The median U-turn is capable of serving higher-volume side streets than a restricted crossing U-turn intersection (signalized J-turn) because side street through traffic is not diverted. Figure 4-14: Median U-Turn Intersection 4.5.1. DETERMINING DELAY AT MEDIAN U-TURN INTERSECTIONS Median U-turn intersections are a good example of the process of calculating delay at complex intersections and comparing that delay to traditional alternatives using travel time and the cordon line approach. Figure 4-15 shows how the travel time for a northbound left-turn movement should be determined at a traditional intersection and a median U-turn intersection using these methods.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4–Case Studies Page 85 Traditional northbound left-turn Northbound left-turn at a median U-turn intersection Figure 4-15: Travel Time Schematic for Traditional and Median U-Turn Intersections As shown, three components make up a vehicle’s travel time within the cordon line. These are: • Running time • Geometric delay • Control delay To fairly compare travel time between alternatives, vehicles must be tracked between the same entry and exit points on the cordon line for each movement. The equation to arrive at total travel time for a movement is shown in Equation 4-1. - Running time - Geometric delay - Control delay

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4 – Case Studies Page 86 Equation 4-1: Total Travel Time Equation 𝑇𝑇𝑇𝑇𝑇𝑇 𝑡𝑡𝑡𝑇 = �𝑇𝑟𝑟𝑟𝑡𝑟𝑟 𝑡𝑡𝑡𝑇 + �𝑟𝑇𝑔𝑡𝑇𝑡𝑇𝑡𝑔 𝑑𝑇𝑇𝑇𝑑 + �𝑔𝑔𝑟𝑡𝑇𝑔𝑇 𝑑𝑇𝑇𝑇𝑑 The comparison of travel time conducted for Case Study 5 during existing conditions is shown in Table 4-61. As shown, the median U-turn intersection has a lower weighted travel time even though out of direction travel is introduced. Table 4-6: Comparison of Travel Time Move- ment PM Volume (vph) Running Time (s) Geometric Delay (s) Control Delay (s) Travel Time (s) Existing Median U-turn Existing Median U-turn Existing Median U-turn Existing Median U-turn EBL 147 34 77 8.9 21.9 62 41 105 140 EBT 698 45 45 0.0 0.0 31 23 76 67 EBR 390 34 34 8.5 8.5 115 21 158 63 WBL 114 28 77 8.9 21.9 42 60 79 159 WBT 1060 43 43 0.0 0.0 36 43 79 87 WBR 199 28 28 8.5 8.5 6 18 42 54 NBL 338 35 74 8.9 21.9 58 43 101 139 NBT 418 20 20 0.0 0.0 245 32 264 52 NBR 48 30 30 8.5 8.5 50 32 89 71 SBL 206 30 59 8.9 21.9 50 70 89 150 SBT 382 20 20 0.0 0.0 80 39 99 58 SBR 130 35 35 8.5 8.5 0 42 43 85 Weighted Average 35 42 3.3 5.8 69 36 107 85 Table 4-7 shows the basic characteristics that were used in the LCCET evaluation. 1It should be noted that the calculation of the individual components of travel time (running time, geometric delay, control delay) is important to this type of analysis. The analyst should ensure that methods are sound and consistent amongst alternatives when comparing life-cycle costs. For this example, broad assumptions were made related to these metrics. For example, geometric delay was assumed to be 8.5 seconds for right-turn movements, 8.9 seconds for left-turn movements, and 11.0 seconds for U-turn movements. The values are based on negotiation distance, negotiation radius, negotiation speed, approach speeds, etc. For these and other metrics, the analyst should ensure that values used are representative of local conditions, based on sound judgment, and consistently calculated between alternatives.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4–Case Studies Page 87 Table 4-7: Case Study Information Summary Alternative: Base Case Median U-Turn Base Analysis Year 2008 Future Analysis Year 2035 Average Annual Daily Traffic (veh/d) Base 40,045 Future 48,054 Total Entering Vehicles (Base) (veh/h) AM 3,304 PM 4,130 Midday n/a Total Entering Vehicles (Future) (veh/h) AM n/a PM 4,956 Midday n/a Annual Trucks Base 5% Future 5% Transit/Bicycles/Pedestrians n/a Delay (Base) (s/veh) AM n/a n/a PM 107 85 Midday n/a n/a Delay (Future) (s/veh) AM n/a n/a PM 131 104 Midday n/a n/a Base Year Safety Performance PDO Crashes n/a n/a Injury Crashes n/a n/a Fatal Crashes n/a n/a Future Year Safety Performance PDO Crashes n/a n/a Injury Crashes n/a n/a Fatal Crashes n/a n/a Planning/Engineering Costs n/a n/a Right-of-way Costs n/a n/a Construction Costs n/a n/a Net Present Value $5,560,511 $4,527,909 Benefits/Costs Estimated capital costs not included in analysis Figure 4-16 illustrates the graphical results of the intersection alternative analysis.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4 – Case Studies Page 88 Figure 4-16: Graphical Output from Intersection Alternative Analysis The life-cycle cost evaluation showed that the median U-turn intersection alternative would cost nearly $1 million less than the existing base alternative over the life of the intersection. This is primarily due to the auto passenger time cost parameter that was used in the comparison, as shown graphically in Exhibit 4-16. 4.6. CASE STUDY 6: HYPOTHETICAL EXAMPLE Case Studies 1 through 5 demonstrated a variety of intersection alternative examples, based on real projects that were identified through local and state agency coordination. While these case studies included many of the cost parameters available in the LCCET, some data were not available for all cost parameters, particularly for parameters such as reliability and emissions. To illustrate the full abilities of the LCCET, this hypothetical example was developed to provide an example that considered the following information: • Vehicle delay; • Variation in vehicle delay (reliability); • Bicycle delay; • Pedestrian delay; • Transit delay; • Crashes; and

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4–Case Studies Page 89 • Emissions. This hypothetical example considered the following intersection alternatives: • Alternative 0: Base case (existing all-way stop-controlled intersection) • Alternative 1: Signalized Intersection • Alternative 2: Roundabout Intersection Table 4-8 summaries the case study information used in the hypothetical example. Table 4-8: Case Study Information Summary Alternative: Base Case Signal Roundabout Base Analysis Year 2014 Future Analysis Year 2035 Average Annual Daily Traffic (veh/d) Base 11,268 Future 17,510 Total Entering Vehicles (Base) (veh/h) AM 868 PM 1,155 Midday n/a Total Entering Vehicles (Future) (veh/h) AM 1,315 PM 1,751 Midday n/a Annual Trucks Base 2% Future 2% Transit/Bicycles/Pedestrians Transit: Existing Users = 1,500 Future Users = 2,273 Bicycles: Existing Users = 750 Future Users = 1,136 Pedestrians: Existing Users = 500 Future Users = 1,000 Delay (Base) (s/veh) AM 12.8 11.1 10.1 PM 17.3 21.4 13.1 Midday n/a n/a n/a Delay (Future) (s/veh) AM 30.2 14.7 21.0 PM 75.6 17.6 48.8 Midday n/a n/a n/a Base Year Safety Performance PDO Crashes 12.0 13.0 11.5 Injury Crashes 4.0 4.5 3.5 Fatal Crashes 0.0 0.05 0.0 Future Year Safety Performance PDO Crashes 18.5 19.0 18.0 Injury Crashes 5.5 6.0 5.0 Fatal Crashes 0.05 0.1 0.05 Planning/Engineering Costs n/a $125,000 $275,000 Operations & Maintenance $49,245 $71,464 $87,879 Right-of-Way Costs n/a $200,000 $300,000 Construction Costs n/a $610,000 $1,650,000 Net Present Value $25,046.797 $34,645,237 $25,133,793 Benefits/Costs n/a -8.20 0.96 Figure 4-17 illustrates the graphical results of the intersection alternative analysis.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4 – Case Studies Page 90 Figure 4-17: Graphical Output from Intersection Alternative Analysis Based on the life-cycle cost evaluation, the following conclusions were identified with the hypothetical example in Case Study 6. • The existing intersection configuration is forecasted to have moderate delays in the future • The benefit-cost ratio of the signalized intersection option shows the least benefit by far • The roundabout option provides slight benefits in delay and safety, but those benefits are offset by the higher initial capital costs • Based on total net present costs, maintaining the existing configuration provides equal costs to a roundabout and less cost than a signalized intersection through the horizon year 4.7. SUMMARY Through coordination with various agencies, case studies were prepared to demonstrate the tool’s value to prospective users and facilitate implementation. The six case studies provide examples of the LCCET functionality and effectiveness for a variety of project types in different geographical locations.

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 4–Case Studies Page 91 This includes a hypothetical case study that further demonstrates some of the unique attributes of the tool, such as the ability to account for emissions, which were not included in the other project examples.