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From page 149... ... Evaluating the Performance of Corridors with Roundabouts Corridor Comparison Document Page A-1 APPENDIX A CORRIDOR COMPARISON DOCUMENT The Corridor Comparison Document (CCD) Read the entire page →
From page 150... ... Evaluating the Performance of Corridors with Roundabouts Page A-2 with three or more "major" intersections that could potentially be controlled with a roundabout or a traffic signal. Throughout the document, "major" intersections are defined as intersections needing roundabout, traffic signal, or stop control. Read the entire page →
From page 151... ... Evaluating the Performance of Corridors with Roundabouts Corridor Comparison Document Page A-3 2.1. PASSENGER CARS Passenger cars often dominate arterial streets, in terms of their percentage of the overall mode split. Read the entire page →
From page 152... ... Evaluating the Performance of Corridors with Roundabouts Page A-4 are also used at roundabouts in some European countries and in at least one US location (Oregon) Read the entire page →
From page 153... ... Evaluating the Performance of Corridors with Roundabouts Corridor Comparison Document Page A-5 2.4. BICYCLES Arterials have historically been designed without bicycle sensitive design elements, such as bicycle lanes or storm drains without openings parallel to the direction of travel. Read the entire page →
From page 154... ... Evaluating the Performance of Corridors with Roundabouts Page A-6 Trucks have greater air quality and noise quality impacts due to their size and weight. The speed of trucks, like other motorized vehicles, is limited by vehicle path radii at roundabouts. Read the entire page →
From page 155... ... Evaluating the Performance of Corridors with Roundabouts Corridor Comparison Document Page A-7 CHAPTER 3: PROJECT-PLANNING PROCESS This chapter is primarily wrien from the perspective of practitioners evaluating alternatives for reconstructing an existing corridor or constructing a new roadway where the alignment has already been determined. In other words, the process presented in this chapter is focused on intersection control and cross section decisions, not roadway alignment decisions. Read the entire page →
From page 156... ... Evaluating the Performance of Corridors with Roundabouts Page A-8 3.1. Read the entire page →
From page 157... ... Evaluating the Performance of Corridors with Roundabouts Corridor Comparison Document Page A-9 is it located? Who will it serve? Read the entire page →
From page 158... ... Evaluating the Performance of Corridors with Roundabouts Page A-10 needs, goals, and objectives in some corridors may predominantly relate to deficiencies for one or several user groups, but not all. Therefore, during this stage of the planning process, planners and engineers should consider the needs of the community and begin to identify relevant performance measures for the corridor -- including those that will vary with roundabouts and traffic signals -- to help assess the performance of each control device. Read the entire page →
From page 159... ... Evaluating the Performance of Corridors with Roundabouts Corridor Comparison Document Page A-11 Tier II – items that apply to many locations (e.g., access management, pedestrian accessibility) Read the entire page →
From page 160... ... Evaluating the Performance of Corridors with Roundabouts Page A-12 Exhibit 3-2: Performance Measures Corridor Comparison Document Read the entire page →
From page 161... ... Evaluating the Performance of Corridors with Roundabouts Corridor Comparison Document Page A-13 Conceptually, the performance measures can be separated into two broad categories: quantitative and qualitative. Quantitative performance measures include delay, predicted crash frequency, and construction cost. Read the entire page →
From page 162... ... Evaluating the Performance of Corridors with Roundabouts Page A-14 a comparison of alternatives with different midblock elements (such as a TWLTL versus a median) when intersection control is the same. Read the entire page →
From page 163... ... Evaluating the Performance of Corridors with Roundabouts Corridor Comparison Document Page A-15 Sometimes, the number of through lanes on a corridor is pre determined. For example, an agency may have a programmed project that calls for a four lane roadway between two points. Read the entire page →
From page 164... ... Evaluating the Performance of Corridors with Roundabouts Page A-16 3.3.3. Refine Preferred Alternative After selecting an alternative, increasingly detailed design activities will begin and culminate with a final design effort to produce construction documents. Read the entire page →
From page 165... ... Evaluating the Performance of Corridors with Roundabouts Corridor Comparison Document Page A-17 apart" (1) Read the entire page →
From page 166... ... Evaluating the Performance of Corridors with Roundabouts Page A-18 Performance Measure Assessment Techniques and Notes Queues The HCM provides procedures for determining queue lengths at signalized, stopcontrolled, and roundabout-controlled intersections. Practitioners may also use deterministic software such as SYNCHRO and SIDRA or simulation software such as SIMTRAFFIC and VISSIM to estimate queue lengths. Read the entire page →
From page 167... ... Evaluating the Performance of Corridors with Roundabouts Corridor Comparison Document Page A-19 Performance Measure Assessment Techniques and Notes Side-Street/ Driveway Traffic Performance at TWSC Intersections Side streets and driveways can experience several operational challenges. If the major-street volume is sufficiently high, side streets and driveways may experience failing levels of delay regardless of their traffic volume. Read the entire page →
From page 168... ... Evaluating the Performance of Corridors with Roundabouts Page A-20 Performance Measure Assessment Techniques and Notes Predicted Vehicle Crash Frequency Chapter 12 of the HSM contains SPFs for segments and intersections of urban and suburban arterials. In general, fewer crashes are expected at a single-lane roundabout than at a signalized intersection. Read the entire page →
From page 169... ... Evaluating the Performance of Corridors with Roundabouts Corridor Comparison Document Page A-21 Environmental Policy Act (SEPA) in many states or the California Environmental Quality Act (CEQA) Read the entire page →
From page 170... ... Evaluating the Performance of Corridors with Roundabouts Page A-22 Performance Measure Assessment Techniques and Notes Construction Costs Pre-construction Costs (such as design) Often this is estimated as a percentage of the construction cost. Read the entire page →
From page 171... ... Evaluating the Performance of Corridors with Roundabouts Corridor Comparison Document Page A-23 Performance Measure Assessment Techniques and Notes Livability Livability often refers to the quality of life experienced by people who live, work, and recreate in a given place. Transportation infrastructure can positively or negatively affect a community's livability. Read the entire page →
From page 172... ... Evaluating the Performance of Corridors with Roundabouts Page A-24 Performance Measure Comments Land-Use Considerations Roadway design choices can influence land-use patterns in a community, and vice versa. A certain alternative may be favorable to a community because it will fit well with existing land-use patterns or it will guide future land use in a manner that is desired. Read the entire page →
From page 173... ... Evaluating the Performance of Corridors with Roundabouts Corridor Comparison Document Page A-25 Benefits: Crash reduction; delay reduction (full day and annual) ; fuel consumption reduction (full day and annual) Read the entire page →
From page 174... ... Evaluating the Performance of Corridors with Roundabouts Page A-26 REFERENCES 1. Transportation Research Board. Read the entire page →
From page 175... ... Evaluating the Performance of Corridors with Roundabouts Example Application #1 Page A-27 EXAMPLE APPLICATION 1. BEECHMONT AVENUE This fictional example application presents a new suburban roadway built to provide access to land and increased connectivity. Read the entire page →
From page 176... ... Evaluating the Performance of Corridors with Roundabouts Page A-28 Example Application #1 planning to extend Beechmont Avenue. Beechmont Avenue is a four lane, minor arterial roadway with a posted speed of 45 miles per hour. Read the entire page →
From page 177... ... Evaluating the Performance of Corridors with Roundabouts Example Application #1 Page A-29 1.1.2. USERS AND TRAFFIC VOLUME The forecast ADT on the Beechmont Avenue extension is 26,000. Read the entire page →
From page 178... ... Evaluating the Performance of Corridors with Roundabouts Page A-30 Example Application #1 for any movement or be close to capacity. The county will assess corridor travel time as well. Read the entire page →
From page 179... ... Evaluating the Performance of Corridors with Roundabouts Example Application #1 Page A-31 Key Performance Measures: Land access and use. Read the entire page →
From page 180... ... Evaluating the Performance of Corridors with Roundabouts Page A-32 Example Application #1 The HSM includes methods to predict roadway segment crashes. Generally speaking, the HSM indicates divided roadway segments with raised medians typically have fewer crashes than undivided roadway segments with TWLTLs. Read the entire page →
From page 181... ... Evaluating the Performance of Corridors with Roundabouts Example Application #1 Page A-33 1.3.1. EVALUATE THE ALTERNATIVES Exhibit 1 4 summarizes an analysis of the three alternatives proposed for Beechmont Avenue using the key performance measures identified in Section 1.1.4. Read the entire page →
From page 182... ... Evaluating the Performance of Corridors with Roundabouts Page A-34 Example Application #1 Perfor- mance Measure Alternative 1 – Signals and TWLTL Alternative 2 – Signals and Median Alternative 3 – Roundabouts Comments Predicted intersection crash frequency (See Section 1.3.1.2) HSM predictive analysis estimates 5.28 auto crashes per year at the northernmost intersection, and similar rates at other intersections. Read the entire page →
From page 183... ... Evaluating the Performance of Corridors with Roundabouts Example Application #1 Page A-35 1.3.1.1. Corridor Travel-Time Analysis Anderson County estimated travel time for Alternative 3 with the procedure illustrated below. Read the entire page →
From page 184... ... Evaluating the Performance of Corridors with Roundabouts Page A-36 Example Application #1 STEP B: DETERMINE FREE FLOW SPEED Initially assume the roundabout influence areas of adjacent roundabouts do not overlap. This assumption is checked in Step D, and addressed in Step E if it proves to be incorrect. Read the entire page →
From page 185... ... Evaluating the Performance of Corridors with Roundabouts Example Application #1 Page A-37 = 42.41 mph Using the downstream sub segment free flow speed model, the estimated FFS for sub segment 1DS follows as: = 42.646 mph STEP C: DETERMINE ROUNDABOUT INFLUENCE AREA LENGTH The length of each roundabout influence area can be estimated using the roundabout influence area models: RIAUS = 165.9 + 13.8* Read the entire page →
From page 186... ... Evaluating the Performance of Corridors with Roundabouts Page A-38 Example Application #1 Roundabout Subsegment Roundabout Influence Area Length (feet) 1 US 329 1 DS 739 2 US 339 2 DS 715 3 US 329 3 DS 709 4 US 327 4 DS 715 5 US 329 5 DS 739 6 US 339 6 DS 739 7 US 339 7 DS 496 For example, the roundabout influence area of sub segment 1US can be calculated using the roundabout influence area model for an upstream sub segment: = 329 feet The roundabout influence area of sub segment 1DS can be calculated using the roundabout influence area model for a downstream sub segment: = 739 feet STEP D: CHECK OVERLAPPING ROUNDABOUT INFLUENCE AREAS Step B assumed roundabout influence areas did not overlap. Read the entire page →
From page 187... ... Evaluating the Performance of Corridors with Roundabouts Example Application #1 Page A-39 STEP E: RECALCULATE FREE FLOW SPEED OF SEGMENTS WITH OVERLAPPING ROUNDABOUT INFLUENCE AREAS Treating sub segment 7DS with OL = 1, the free flow speed is now 34.9 mph. STEP F: SELECT CONTROLLING FREE FLOW SPEED FROM EACH PAIR OF SUB SEGMENTS This step takes the minimum free flow speed within each pair of sub segments for use in future calculations. Read the entire page →
From page 188... ... Evaluating the Performance of Corridors with Roundabouts Page A-40 Example Application #1 STEP H: DETERMINE GEOMETRIC DELAY OF EACH SUB SEGMENT Using these controlling free flow speeds, the geometric delay incurred over the roundabout influence area can be estimated for each segment using the following model: Delaygeom, US= 1.57 + 0.11* Read the entire page →
From page 189... ... Evaluating the Performance of Corridors with Roundabouts Example Application #1 Page A-41 = 4.2 seconds STEP I: DETERMINE IMPEDED DELAY OF EACH SUB SEGMENT Using the controlling free flow speeds and traffic characteristics, impeded delay (i.e., the delay incurred due to traffic conditions and not geometric constraints) of each sub segment is now calculated. Read the entire page →
From page 190... ... Evaluating the Performance of Corridors with Roundabouts Page A-42 Example Application #1 For example, the impeded delay of sub segment 1US can be calculated using the impeded delay model for an upstream sub segment: = 4.2 seconds The impeded delay of sub segment 1DS can be calculated using the impeded delay model for a downstream sub segment: = 5.5 seconds STEP J: AGGREGATE SUB SEGMENT PERFORMANCE MEASURES TO CHAPTER 17 SEGMENT LEVEL The average travel time over each segment is calculated by adding the following elements of each (non overlapping) sub segment: 1. Read the entire page →
From page 191... ... Evaluating the Performance of Corridors with Roundabouts Example Application #1 Page A-43 After the travel times are computed, the average segment travel speed is computed by dividing each segment length by the respective average travel time. This performance measure is consistent with the methodology in HCM Chapter 17. Read the entire page →
From page 192... ... Evaluating the Performance of Corridors with Roundabouts Page A-44 Example Application #1 because the entire segment lies within the influence area of Roundabout 7; i.e., vehicles are accelerating or decelerating over the entire sub segment. FACILITY LEVEL OF SERVICE To aggregate the travel times over the entire facility, HCM Chapter 16 is used directly. Read the entire page →
From page 193... ... Evaluating the Performance of Corridors with Roundabouts Example Application #1 Page A-45 Additional equations are provided in the HSM for determining the proportion of total crashes that are Fatal and Injury (FI) crashes and Property Damage–Only (PDO) Read the entire page →
From page 194... ... Evaluating the Performance of Corridors with Roundabouts Page A-46 Example Application #1 As shown in Exhibit 1 15, the CMF for converting a suburban signalized intersection to a two lane roundabout is 0.33, with a standard error of 0.05. With 95% confidence, the crashes are reduced by a factor of: 0.33 ± (2 * Read the entire page →
From page 195... ... Evaluating the Performance of Corridors with Roundabouts Example Application #2 Page A-47 EXAMPLE APPLICATION 2. OCEAN DRIVE This fictional example application presents a community enhancement project on an urban corridor. Read the entire page →
From page 196... ... Evaluating the Performance of Corridors with Roundabouts Page A-48 Example Application #2 2.1.1. UNDERSTANDING OF CONTEXT Ocean Drive is a ﬁve lane roadway with two travel lanes in each direction, a two way left turn lane, and parallel on street parking. Read the entire page →
From page 197... ... Evaluating the Performance of Corridors with Roundabouts Example Application #2 Page A-49 speeds along Ocean Drive are approximately 40 miles per hour. There is relatively lile east west traffic crossing the corridor. Read the entire page →
From page 198... ... Evaluating the Performance of Corridors with Roundabouts Page A-50 Example Application #2 and Tier II and III measures like crosswalk length and aesthetics. Performance measures of strong interest to the community are generally prioritized over those of lesser interest to the community. Read the entire page →
From page 199... ... Evaluating the Performance of Corridors with Roundabouts Example Application #2 Page A-51 2.1.4.4. Cost Performance Measures Any build alternative will have capital construction and annual maintenance costs. Read the entire page →
From page 200... ... Evaluating the Performance of Corridors with Roundabouts Page A-52 Example Application #2 2.2.1.1. Brainstorming of Strategies The community engagement process resulted in several strategies for achieving project goals: Road diet: Reduce the number of lanes on Ocean Drive, add bike lanes, potentially widen sidewalks, potentially narrow travel lanes. Read the entire page →
From page 201... ... Evaluating the Performance of Corridors with Roundabouts Example Application #2 Page A-53 2.2.1.2. Preliminary Operations Analysis Road Diet Strategy: The ADT of Ocean Drive is 16,000 veh/day. Read the entire page →
From page 202... ... Evaluating the Performance of Corridors with Roundabouts Page A-54 Example Application #2 Roundabout Strategy: City engineers evaluated the geometric and operational feasibility of roundabouts. Exhibit 2 7 presents the available right of way at an intersection along Ocean Drive. Read the entire page →
From page 203... ... Evaluating the Performance of Corridors with Roundabouts Example Application #2 Page A-55 The 125 foot dimension depicted in Exhibit 2 7 would accommodate an inscribed circle diameter (ICD) of approximately 110 feet, plus sidewalks beyond the roundabout. Read the entire page →
From page 204... ... Evaluating the Performance of Corridors with Roundabouts Page A-56 Example Application #2 2.2.1.3. Initial Layouts Based on the initial operational analysis of the strategies, the city developed three concepts for corridor improvements: 1. Read the entire page →
From page 205... ... Evaluating the Performance of Corridors with Roundabouts Example Application #2 Page A-57 Detailed analysis of the operations and geometrics at the northern and southern ends of the couplet will be needed. At the southern end, Palm Drive will need to be connected to the Ocean Drive/Coconut Lane intersection, and the intersection will need to be reconfigured. Read the entire page →
From page 206... ... Evaluating the Performance of Corridors with Roundabouts Page A-58 Example Application #2 Exhibit 2-9: Typical Ocean Drive Intersection and Road Segment, Alternative 1 Read the entire page →
From page 207... ... Evaluating the Performance of Corridors with Roundabouts Example Application #2 Page A-59 Exhibit 2-10A: Alternative 2 Overview Read the entire page →
From page 208... ... Evaluating the Performance of Corridors with Roundabouts Page A-60 Example Application #2 Exhibit 2-10B: Typical Ocean Drive Intersection and Road Segment, Alternative 2 Read the entire page →
From page 209... ... Evaluating the Performance of Corridors with Roundabouts Example Application #2 Page A-61 Exhibit 2-11: Typical Ocean Drive Intersection and Road Segment, Alternative 3 Read the entire page →
From page 210... ... Evaluating the Performance of Corridors with Roundabouts Page A-62 Example Application #2 2.3. ALTERNATIVES ANALYSIS Steps in the Alternatives Analysis phase of the Project-Planning Process (refer to Corridor Comparison Document, Chapter 3) Read the entire page →
From page 211... ... Evaluating the Performance of Corridors with Roundabouts Example Application #2 Page A-63 Performance Measure Alternative 1 – Road Diet with Signals and TWSC Alternative 2 – One-Way Couplet with Signals and TWSC Alternative 3 – Road Diet with Roundabouts Comments Peak-hour intersection LOS During the a.m. Read the entire page →
From page 212... ... Evaluating the Performance of Corridors with Roundabouts Page A-64 Example Application #2 Perfor- mance Measure Alternative 1 – Road Diet with Signals and TWSC Alternative 2 – One-Way Couplet with Signals and TWSC Alternative 3 – Road Diet with Roundabouts Comments Anticipated impact on businesses Business owners generally believe this alternative would result in a modest increase in profits due to the increased parking and enhanced pedestrian environment. Business owners are concerned that removing northbound traffic from Ocean Drive would decrease the visibility of their businesses and thus their profits. Read the entire page →
From page 213... ... Evaluating the Performance of Corridors with Roundabouts Example Application #2 Page A-65 Perfor- mance Measure Alternative 1 – Road Diet with Signals and TWSC Alternative 2 – One-Way Couplet with Signals and TWSC Alternative 3 – Road Diet with Roundabouts Comments Aesthetics By changing the cross-section of the roadway, this alternative creates the opportunity for aesthetic improvements such as landscaping and decorative pavement. This alternative creates the opportunity for aesthetic improvements on both Ocean Drive and Palm Drive. Read the entire page →
From page 214... ... Evaluating the Performance of Corridors with Roundabouts Page A-66 Example Application #2 = 36.1 mph = 36.4 mph Using free flow speed values, the corresponding roundabout influence areas can be computed as follows: = 242 feet = 544 feet These values indicate that the influence areas do not overlap, so the assumption in Step B was correct. Intersections on Ocean Drive are spaced between 600 and 800 feet apart. Read the entire page →
From page 215... ... Evaluating the Performance of Corridors with Roundabouts Example Application #3 Page A-67 EXAMPLE APPLICATION 3. US 7 This fictional example application presents a context sensitive access management project on a rural corridor beginning to suburbanize. Read the entire page →
From page 216... ... Evaluating the Performance of Corridors with Roundabouts Page A-68 Example Application #3 3.1.1. UNDERSTANDING OF CONTEXT Elk Grove is a historically rural town that experienced substantially increased population growth the past decade. Read the entire page →
From page 217... ... Evaluating the Performance of Corridors with Roundabouts Example Application #3 Page A-69 3.1.2. USERS AND TRAFFIC VOLUME US 7 serves a variety of users. Read the entire page →
From page 218... ... Evaluating the Performance of Corridors with Roundabouts Page A-70 Example Application #3 per hour. There is relatively lile east west traffic crossing the corridor, and only SR 272 has more than 150 side street vehicles in the peak hour. Read the entire page →
From page 219... ... Evaluating the Performance of Corridors with Roundabouts Example Application #3 Page A-71 The DOT has level of service and volume to capacity (v/c) ratio standards for new or reconstructed state highways, and DOT policy requires these standards to be assessed at the planning stage of the project. Read the entire page →
From page 220... ... Evaluating the Performance of Corridors with Roundabouts Page A-72 Example Application #3 3.1.4.6. Other Performance Measures The DOT initiated this project to beer manage access on US 7. Read the entire page →
From page 221... ... Evaluating the Performance of Corridors with Roundabouts Example Application #3 Page A-73 through right lane and a left turn lane on US 7. The analysis determined this lane configuration is adequate to meet DOT performance criteria. Read the entire page →
From page 222... ... Evaluating the Performance of Corridors with Roundabouts Page A-74 Example Application #3 Exhibit 3-3: Alternative 1 Overview Read the entire page →
From page 223... ... Evaluating the Performance of Corridors with Roundabouts Example Application #3 Page A-75 Exhibit 3-4: Representative Segment of Alternative 1 Read the entire page →
From page 224... ... Evaluating the Performance of Corridors with Roundabouts Page A-76 Example Application #3 Exhibit 3-5: Alternative 2 Overview Read the entire page →
From page 225... ... Evaluating the Performance of Corridors with Roundabouts Example Application #3 Page A-77 Exhibit 3-6: Representative Segment of Alternative 2 Read the entire page →
From page 226... ... Evaluating the Performance of Corridors with Roundabouts Page A-78 Example Application #3 Exhibit 3-7: Alternative 3 Overview Read the entire page →
From page 227... ... Evaluating the Performance of Corridors with Roundabouts Example Application #3 Page A-79 3.3. ALTERNATIVES ANALYSIS Steps in the Alternatives Analysis phase of the Project-Planning Process (refer to Corridor Comparison Document, Chapter 3) Read the entire page →
From page 228... ... Evaluating the Performance of Corridors with Roundabouts Page A-80 Example Application #3 Performance Measure Alternative 1 – Signals and TWLTL Alternative 2 – Roundabouts and Median Alternative 3 – Two-Lane Bypass Comments LOS During the a.m. Read the entire page →
From page 229... ... Evaluating the Performance of Corridors with Roundabouts Example Application #3 Page A-81 Perfor- mance Measure Alternative 1 – Signals and TWLTL Alternative 2 – Roundabouts and Median Alternative 3 – Two-Lane Bypass Comments Conflict points The number of intersection conflict points remains approximately the same. A four-leg intersection with single-lane approaches has 32 auto-auto conflict points and 24 autopedestrian conflict points. Read the entire page →
From page 230... ... Evaluating the Performance of Corridors with Roundabouts Page A-82 Example Application #3 Perfor- mance Measure Alternative 1 – Signals and TWLTL Alternative 2 – Roundabouts and Median Alternative 3 – Two-Lane Bypass Comments Impacts to public facilities The DOT will purchase a 7-footwide strip of land from a local school to accommodate a widened US 7. This is currently part of a lawn and impacts are considered minimal. Read the entire page →
From page 231... ... Evaluating the Performance of Corridors with Roundabouts Example Application #3 Page A-83 Perfor- mance Measure Alternative 1 – Signals and TWLTL Alternative 2 – Roundabouts and Median Alternative 3 – Two-Lane Bypass Comments Aesthetics Streetscape improvements such as new sidewalks and curbs will improve the appearance of the corridor. Alternative 2 includes many of the same streetscape improvements as Alternative 1. Read the entire page →
From page 232... ... Evaluating the Performance of Corridors with Roundabouts Page A-84 Example Application #3 3.3.1.1. Roundabout Influence Area Length Computation Example Roundabout influence area was calculated for one of the roundabouts on US 7 to get a sense of the extent of areas in which speeds will be reduced due to the presence of roundabouts. Read the entire page →
From page 233... ... Evaluating the Performance of Corridors with Roundabouts Example Application #3 Page A-85 Maintenance of these elements was a concern of the DOT. The DOT selected Alternative 2 based on access management benefits and support from the community. Read the entire page →
From page 234... ... Evaluating the Performance of Corridors with Roundabouts Example Application #4 Page A-87 EXAMPLE APPLICATION 4. STEVENS STREET This fictional example application presents a suburban corridor being rebuilt for maintenance reasons. Read the entire page →
From page 235... ... Evaluating the Performance of Corridors with Roundabouts Page A-88 Example Application #4 Stevens Street, which previously served as the primary route between the two cities. The segment of Stevens Street between the Falls to Fort Expressway and SR 71 is nearly ﬁve miles long and has 15 signalized intersections. Read the entire page →
From page 236... ... Evaluating the Performance of Corridors with Roundabouts Example Application #4 Page A-89 4.1.3. PROJECT CATALYST AND GOALS Stevens Street is in need of maintenance. Read the entire page →
From page 237... ... Evaluating the Performance of Corridors with Roundabouts Page A-90 Example Application #4 schools in the project area away from Stevens Street. It is unlikely these facilities will be impacted. Read the entire page →
From page 238... ... Evaluating the Performance of Corridors with Roundabouts Example Application #4 Page A-91 Fort Nestor considered three alternatives for Stevens Street: 1. Alternative #1 rebuilds the pavement of the existing six lane roadway and replaces some signal equipment at the end of its life cycle. Read the entire page →
From page 239... ... Evaluating the Performance of Corridors with Roundabouts Page A-92 Example Application #4 The city also developed plan view layouts of the alternatives to assess right of way needs and perform initial cost estimates. These layouts are omitted from the example application for brevity. Read the entire page →
From page 240... ... Evaluating the Performance of Corridors with Roundabouts Example Application #4 Page A-93 Perfor- mance Measure Alternative 1 – Rebuild 6-Lane Existing Alternative 2 – 4-Lane with Signals Alternative 3 – 4-Lane with Roundabouts Comments Intersection capacity All signalized intersections have a v/c of 0.73 or less. All signalized intersections have a v/c of 0.86 or less. Read the entire page →
From page 241... ... Evaluating the Performance of Corridors with Roundabouts Page A-94 Example Application #4 Perfor- mance Measure Alternative 1 – Rebuild 6-Lane Existing Alternative 2 – 4-Lane with Signals Alternative 3 – 4-Lane with Roundabouts Comments Estimated capital construction cost $5 million. $19 million. Read the entire page →
From page 242... ... Evaluating the Performance of Corridors with Roundabouts Example Application #4 Page A-95 Perfor- mance Measure Alternative 1 – Rebuild 6-Lane Existing Alternative 2 – 4-Lane with Signals Alternative 3 – 4-Lane with Roundabouts Comments Overall public opinion There is little support for this alternative. Approximately half of attendees to public meetings favor this alternative. Read the entire page →
From page 243... ... Evaluating the Performance of Corridors with Roundabouts Page A-96 Example Application #4 Unfortunately, Fort Nestor had only $25 million available for the Stevens Street project. This was enough to fund Alternative 2, but less than half of the estimated total cost (ROW, pre construction, construction) Read the entire page →
From page 244... ... Abbreviations and acronyms used without deﬁnitions in TRB publications: A4A Airlines for America AAAE American Association of Airport Executives AASHO American Association of State Highway Officials AASHTO American Association of State Highway and Transportation Officials ACI–NA Airports Council International–North America ACRP Airport Cooperative Research Program ADA Americans with Disabilities Act APTA American Public Transportation Association ASCE American Society of Civil Engineers ASME American Society of Mechanical Engineers ASTM American Society for Testing and Materials ATA American Trucking Associations CTAA Community Transportation Association of America CTBSSP Commercial Truck and Bus Safety Synthesis Program DHS Department of Homeland Security DOE Department of Energy EPA Environmental Protection Agency FAA Federal Aviation Administration FHWA Federal Highway Administration FMCSA Federal Motor Carrier Safety Administration FRA Federal Railroad Administration FTA Federal Transit Administration HMCRP Hazardous Materials Cooperative Research Program IEEE Institute of Electrical and Electronics Engineers ISTEA Intermodal Surface Transportation Efficiency Act of 1991 ITE Institute of Transportation Engineers MAP-21 Moving Ahead for Progress in the 21st Century Act (2012) NASA National Aeronautics and Space Administration NASAO National Association of State Aviation Officials NCFRP National Cooperative Freight Research Program NCHRP National Cooperative Highway Research Program NHTSA National Highway Traffic Safety Administration NTSB National Transportation Safety Board PHMSA Pipeline and Hazardous Materials Safety Administration RITA Research and Innovative Technology Administration SAE Society of Automotive Engineers SAFETEA-LU Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (2005) Read the entire page →

From page 149...

... Evaluating the Performance of Corridors with Roundabouts Corridor Comparison Document Page A-1 APPENDIX A CORRIDOR COMPARISON DOCUMENT The Corridor Comparison Document (CCD)