Chapter 19 Roundabouts 19.0 Introduction
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Module 6. Hov Treatments
Manual TABLE OF CONTENTS Module 6. TABLE OF CONTENTS MODULE 6. HOV TREATMENTS TABLE OF CONTENTS 6.1 INTRODUCTION ............................................ 6-5 TREATMENTS ..................................................... 6-6 MODULE OBJECTIVES ............................................. 6-6 MODULE SCOPE ................................................... 6-7 6.2 DESIGN PROCESS .......................................... 6-7 IDENTIFY PROBLEMS/NEEDS ....................................... 6-7 IDENTIFICATION OF PARTNERS .................................... 6-8 CONSENSUS BUILDING ........................................... 6-10 ESTABLISH GOALS AND OBJECTIVES ............................... 6-10 ESTABLISH PERFORMANCE CRITERIA / MOES ....................... 6-10 DEFINE FUNCTIONAL REQUIREMENTS ............................. 6-11 IDENTIFY AND SCREEN TECHNOLOGY ............................. 6-11 System Planning ................................................. 6-13 IMPLEMENTATION ............................................... 6-15 EVALUATION .................................................... 6-16 6.3 TECHNIQUES AND TECHNOLOGIES .................. 6-18 HOV FACILITIES ................................................. 6-18 Operational Considerations ......................................... 6-18 HOV Roadway Operations ...................................... 6-20 Operating Efficiency .......................................... 6-20 Considerations for 2+ Versus 3+ Occupancy Requirement ............. 6-20 Hours of Operations .......................................... -
Evaluation of Concrete Pavements with Tied Shoulders Or Widened Lanes Bert E
39 19. K. Y. Kung. A New Method in Correlation Study of vision of Pavements. Proc., 3rd International Con Pavement Deflection and Cracking. Proc., 2nd In ference on Structural Design of Asphalt Pavements, ternational Conference on Structural Design of 1972, pp. 1188-1205. Asphalt Pavements, 1967, pp. 1037-1046. 20. P. H. Leger and P. Autret. The Use of Deflection Publication of this paper sponsored by Committee on Pavement Condi Measurements for the Structural Design and Super- tion Evaluation. Evaluation of Concrete Pavements With Tied Shoulders or Widened Lanes Bert E. Colley, Claire G. Ball, and Pichet Arriyavat, Portland Cement Association Field and laboratory pavements were instrumented and load tested to reducing pavement performance, Because of this prob evaluate the effect of widened lanes, concrete shoulders, and slab thick lem, several states have installed costly longitudinal ness on measured strains and deflectfons. Eight slabs were tested in the and transverse drainage systems. Thus, concrete field and two in the laboratory. Pavement slabs were 203, 229, or 254 shoulders and widened lanes have the potential for curing mm (8, 9, or 10 in) thick. Other major design variables included the width of lane widening, the presence or absence of dowels or of a con many drainage problems as well as providing additional crete shoulder, joint spacing, and the type of shoulder joint construc slab strength. tion. Generally, there was good agreement between measured strains and Many design features contribute to pavement life. values calculated by using Westergaard's theoretical equations. Concrete The effect of some of these features can be evaluated shoulders were effective in reducing the magnitude of measured strains analytically. -
A Guide for HOT Lane Development FHWA
U.S. Department of Transportation Federal Highway Administration A Guide for HOT LANE DEVELOPMENT A Guide for HOT LANE DEVELOPMENT BY WITH IN PARTNERSHIP WITH U.S. Department of Transportation Federal Highway Administration PRINCIPAL AUTHORS Benjamin G. Perez, AICP PB CONSULT Gian-Claudia Sciara, AICP PARSONS BRINCKERHOFF WITH CONTRIBUTIONS FROM T. Brent Baker Stephanie MacLachlin PB CONSULT PB CONSULT Kiran Bhatt Carol C. Martsolf KT ANALYTICS PARSONS BRINCKERHOFF James S. Bourgart Hameed Merchant PARSONS BRINCKERHOFF HOUSTON METRO James R. Brown John Muscatell PARSONS BRINCKERHOFF COLORADO DEPARTMENT OF TRANSPORTATION Ginger Daniels John O’Laughlin TEXAS TRANSPORTATION INSTITUTE PARSONS BRINCKERHOFF Heather Dugan Bruce Podwal COLORADO DEPARTMENT OF TRANSPORTATION PARSONS BRINCKERHOFF Charles Fuhs Robert Poole PARSONS BRINCKERHOFF REASON PUBLIC POLICY INSTITUTE Ira J. Hirschman David Pope PB CONSULT PARSONS BRINCKERHOFF David Kaplan Al Schaufler SAN DIEGO ASSOCIATION OF GOVERNMENTS PARSONS BRINCKERHOFF Hal Kassoff Peter Samuel PARSONS BRINCKERHOFF TOLL ROADS NEWSLETTER Kim Kawada William Stockton SAN DIEGO ASSOCIATION OF GOVERNMENTS TEXAS TRANSPORTATION INSTITUTE Tim Kelly Myron Swisher HOUSTON METRO COLORADO DEPARTMENT OF TRANSPORTATION Stephen Lockwood Sally Wegmann PB CONSULT TEXAS DEPARTMENT OF TRANSPORTATION Chapter 1 Hot Lane Concept And Rationale........................................................................2 1.1 HOT lanes Defined .................................................................................................2 -
Chapter 9 Intersections
2005 Intersections CHAPTER 9 INTERSECTIONS 9.0 INTRODUCTION Intersections are intended to operate with vehicles, pedestrians, and bicycles proceeding in many directions, often at the same time. At such locations, traffic movements on two or more facilities are required to occupy a common area. It is this unique characteristic of intersections, the repeated occurrence of conflicts, that is the basis for most intersection design standards, criteria, and proper operating procedures. An intersection is defined as the general area where two or more highways join or cross, including the roadway and roadside facilities for traffic movements within it. Each highway radiating from an intersection and forming part of it is an intersection leg. The common intersection of two highways crossing each other has four legs. It is not recommended that an intersection have more than four legs. An intersection is an important part of a highway system because, to a great extent, the efficiency, safety, speed, cost of operation, and capacity depend on its design. Each intersection involves through or cross-traffic movements on one or more of the highways concerned and may involve turning movements between these highways. These movements may be handled by various means, such as signals, signing, and channelization, depending on the type of intersection. 9.1 GENERAL DESIGN CONSIDERATIONS AND OBJECTIVES The main objective of intersection design is to reduce the potential conflicts between motor vehicles, bicycles, pedestrians, and facilities while facilitating the convenience, ease, and comfort of the people traversing the intersection. The design should be fitted closely to the natural transitional paths and operating characteristics of the users. -
Contruction of Concrete Shoulders
Construction of Concrete Shoulders Ralph L. D uncan Field Engineer, Bureau of Construction Illinois Division of Highways Springfield, Illinois INTRODUCTION Illinois has constructed concrete shoulders on portions of three con tracts. During the 1963-1964 construction season, our contracts per mitted the contractor the option of the type of stabilizing agent to use with a gravel or crushed stone material to produce a stabilized shoulder. We had progressed to this high type shoulder as have most highway departments in order to try to reduce maintenance problems, eliminate drop-offs at pavement edges, and provide a year-round safe recovery and emergency stopping areas. W e have on the Illinois highway system earth shoulders, gravel shoulders, crushed stone shoulders, cement aggre gate mixtures (or CAM ) shoulders, bituminous aggregate mixtures (or BAM) shoulders, and pozzolanic mixtures (or PA M ) shoulders. None of these shoulders have proven to be trouble-free. FIRST CONCRETE SHOULDERS IN ILLINOIS—1965 In the spring of 1965, a contractor requested the division of high ways to consider a proposal to place Portland cement concrete shoulders in place of the options provided in the contract. After consideration by the division, it was decided to permit this change in plans. W e hoped to determine the extent of any construction problems and by observation, in future years, to see what maintenance problems might develop. This first construction of Portland cement concrete shoulders is located just north of East Peoria on U.S. 150 between Interstate 74 and Illinois 87. The project is approximately five miles long. The roadway begins at the urban limits of East Peoria and varies from a 4-foot concrete median to a 40-foot depressed median as it leaves the urban area. -
Access Control
Access Control Appendix D US 54 /400 Study Area Proposed Access Management Code City of Andover, KS D1 Table of Contents Section 1: Purpose D3 Section 2: Applicability D4 Section 3: Conformance with Plans, Regulations, and Statutes D5 Section 4: Conflicts and Revisions D5 Section 5: Functional Classification for Access Management D5 Section 6: Access Control Recommendations D8 Section 7: Medians D12 Section 8: Street and Connection Spacing Requirements D13 Section 9: Auxiliary Lanes D14 Section 10: Land Development Access Guidelines D16 Section 11: Circulation and Unified Access D17 Section 12: Driveway Connection Geometry D18 Section 13: Outparcels and Shopping Center Access D22 Section 14: Redevelopment Application D23 Section 15: Traffic Impact Study Requirements D23 Section 16: Review / Exceptions Process D29 Section 17: Glossary D31 D2 Section 1: Purpose The Transportation Research Board Access Management Manual 2003 defines access management as “the systematic control of the location, spacing, design, and operations of driveways, median opening, interchanges, and street connections to a roadway.” Along the US 54/US-400 Corridor, access management techniques are recommended to plan for appropriate access located along future roadways and undeveloped areas. When properly executed, good access management techniques help preserve transportation systems by reducing the number of access points in developed or undeveloped areas while still providing “reasonable access”. Common access related issues which could degrade the street system are: • Driveways or side streets in close proximity to major intersections • Driveways or side streets spaced too close together • Lack of left-turn lanes to store turning vehicles • Deceleration of turning traffic in through lanes • Traffic signals too close together Why Access Management Is Important Access management balances traffic safety and efficiency with reasonable property access. -
Simulation and Experimental Analyses of Microscopic Traffic
applied sciences Article Simulation and Experimental Analyses of Microscopic Traffic Characteristics under a Contraflow Strategy Leyu Wei 1, Jinliang Xu 1,*, Tian Lei 1,2, Menghui Li 1,3 , Xingliang Liu 1 and Haoru Li 1 1 School of Highway, Chang’an University, Xi’an 710064, China 2 Civil, Architectural and Environmental Engineering, University of Texas at Austin, Austin 78712, USA 3 China Harbour Engineering Company Limited, No. 9 Chunxiu Road, Dongcheng District, Beijing 100027, China * Correspondence: [email protected]; Tel.: +86-029-13709208917 Received: 28 April 2019; Accepted: 25 June 2019; Published: 29 June 2019 Featured Application: This work contributes to improving the effectiveness of the contraflow road traffic strategy for mass evacuation in the aftermath of a natural or anthropogenic disaster. Abstract: Contraflow is a common traffic strategy used to improve the capacity of outbound roads during mass evacuation. Previous studies have focused on the contraflow network configuration, travel time, and number of evacuated vehicles on a macroscopic level. Only a few researchers have considered microscopic factors, such as the contraflow characteristics and moving bottlenecks caused by coaches and trucks. In this study, the effects of the contraflow strategy were investigated through field experiments and traffic simulations. Traffic data were collected from highway segments where trucks were forbidden under regular and contraflow conditions for analysis of the traffic characteristics and the effects of coach moving bottlenecks. The results demonstrate that the capacity and flow speed of contraflow lanes are lower than normal lanes, owing to the narrow cross sections and unfamiliar driving environment. The moving bottlenecks also reduced the speed of passenger car platoons by approximately 5–20 km/h. -
17346 1 Special Marking Areas
4" 4" 4" 4" 4" 4" 8' 8' 8' 8' 8' 8' 4" 34 s.f. 22 s.f. 23 s.f. 24 s.f. 20 s.f. 26 s.f. 13 s.f. 20 s.f. 20 s.f. 23 s.f. 22 s.f. 20 s.f. 4" 4" 4" 4" 4" 4" 3'-4" 3'-4" ' ' 5 R2 ' R1 7 5 ' " ' 4" ' 5 6 3 10' 3 - ' R1 6" " 7 ' 6 " 3 - ' ' 9 1 ' 9 8 - ' ' 3 4" ' " ' 5 " 2 4 2 5 6 ' 1 3 - 5 ' " R2 . 4 9 6 - ' ' " ' 1' 1 7 4 8 3 " 5 . R - ' 1' 1' 3 3'-4" 3'-8" 5 2 2 8" R R1=3'3.375" R1=2' 11" ' R2=2'3.563" 3' 1' 5 . R2=1' 11" 6 6'-4" 1 Preferential Lane Through Turn Symbol R1=3'3.375" U Turn Lane-Use Lane-Use R2=2'3.563" Lane-Use Arrow Arrow 11 s.f. Arrow 12 s.f. 17 s.f. Turn and Through 27 s.f. Lane-Use Right Turn Arrow To Be Reversed. Arrow DIMENSIONS ARE WITHIN 1" ± 30" 29 s.f. Wrong-Way 4" PAVEMENT ARROW AND MESSAGE DETAILS NOTE: When arrow and pavement message are used together, the arrow Arrow shall be located down stream of the pavement message and shall be n separated from the pavement message by a distance of 25' (Base of the g 24 s.f. d . arrow to the base of the message). Stop message shall be placed 25' 1 0 from back of stop line. -
Safety Evaluation of Centerline Plus Shoulder Rumble Strips
Safety Evaluation of Centerline Plus Shoulder Rumble Strips PUBLICATION NO. FHWA-HRT-15-048 JUNE 2015 Research, Development, and Technology Turner-Fairbank Highway Research Center 6300 Georgetown Pike McLean, VA 22101-2296 FOREWORD The research documented in this report was conducted as part of the Federal Highway Administration (FHWA) Evaluation of Low-Cost Safety Improvements Pooled Fund Study (ELCSI–PFS). The FHWA established this pooled fund study in 2005 to conduct research on the effectiveness of the safety improvements identified by the National Cooperative Highway Research Program Report 500 Guides as part of the implementation of the American Association of State Highway and Transportation Officials Strategic Highway Safety Plan. The ELCSI-PFS studies provide a crash modification factor (CMF) and benefit-cost (B/C) economic analysis for each of the targeted safety strategies identified as priorities by the pooled fund member states. The combined application of centerline and shoulder rumble strips evaluated under this pooled fund study is intended to reduce the frequency of crashes by alerting drivers that they are about to leave the travelled lane. Geometric, traffic, and crash data were obtained at treated two-lane rural road locations in Kentucky, Missouri, and Pennsylvania. The results of this evaluation show that head-on, run-off-road, and sideswipe-opposite-direction crashes were significantly reduced, and application of centerline and shoulder rumble strips also has potential to reduce crash severity for all types of crashes. Monique R. Evans, P.E. Director, Office of Safety Research and Development Notice This document is disseminated under the sponsorship of the U.S. -
Residential Street Standards & Neighborhood Traffic Control
Residential Street Standards & Neighborhood Traffic Control: A Survey of Cities' Practices and Public Officials' Attitudes Eran Ben-Joseph Institute of Urban and Regional Planning University of California at Berkeley Abstract The failure of the local street system to provide livability and safety in the residential environment can be seen in the application of neighborhood traffic management programs by local authorities to mitigate traffic problems. In order to further identify the extent of the conflict associated with "livability" and geometrical design of residential street, the following issues are examined: (1) Existing and proposed residential streets standards and regulations as practiced by various cities and their evaluation by public and city officials. (2) Traffic problems associated with residential streets and their mitigation through traffic management and control programs. Data are collected from Public Works and Traffic Engineering Departments of 56 Californian cities and 19 cities nation-wide. The findings show that most cities are still adhering to published street standards as recommended by different professional and federal organizations. Although some city officials see the need to amend certain aspects of their regulations and create a more flexible framework for street design, most of them believe that the current practice is satisfactory. Yet, the extant of residents' complaints about traffic problems on their streets might indicate an inconsistency between professional practice, as manifested in street design, and its actual performance as experienced by the residents. This can also be seen in the application of traffic control devices used by local authorities to mitigate these problems of which the most common are the installation of speed humps and 4-way stop signs. -
Intersection Geometric Design
Intersection Geometric Design Course No: C04-033 Credit: 4 PDH Gregory J. Taylor, P.E. Continuing Education and Development, Inc. 22 Stonewall Court Woodcliff Lake, NJ 07677 P: (877) 322-5800 [email protected] Intersection Geometric Design INTRODUCTION This course summarizes and highlights the geometric design process for modern roadway intersections. The contents of this document are intended to serve as guidance and not as an absolute standard or rule. When you complete this course, you should be familiar with the general guidelines for at-grade intersection design. The course objective is to give engineers and designers an in-depth look at the principles to be considered when selecting and designing intersections. Subjects include: 1. General design considerations – function, objectives, capacity 2. Alignment and profile 3. Sight distance – sight triangles, skew 4. Turning roadways – channelization, islands, superelevation 5. Auxiliary lanes 6. Median openings – control radii, lengths, skew 7. Left turns and U-turns 8. Roundabouts 9. Miscellaneous considerations – pedestrians, traffic control, frontage roads 10. Railroad crossings – alignments, sight distance For this course, Chapter 9 of A Policy on Geometric Design of Highways and Streets (also known as the “Green Book”) published by the American Association of State Highway and Transportation Officials (AASHTO) will be used primarily for fundamental geometric design principles. This text is considered to be the primary guidance for U.S. roadway geometric design. Copyright 2015 Gregory J. Taylor, P.E. Page 2 of 56 Intersection Geometric Design This document is intended to explain some principles of good roadway design and show the potential trade-offs that the designer may have to face in a variety of situations, including cost of construction, maintenance requirements, compatibility with adjacent land uses, operational and safety impacts, environmental sensitivity, and compatibility with infrastructure needs. -
Chapter 540 HOV and Transit
Chapter 540 HOV and Transit 540.1 General Chapter540.2 540 References HOV and Transit 540.3 Design Considerations 540.4 Transit Facilities 540.01 General540.5 Commuter Rail 540.04 Transit Facilities 540.02 References540.6 HOVs and Taxis 540.05 Commuter Rail 540.03 Design Considerations 540.06 HOVs and Taxis 540.1 General 540.01 GeneralThis chapter provides guidance and information for designing high-occupancy vehicle (HOV) andThis transit chapterfacilities. providesHOV guidance and transit andfacilities informationinclude fortransit designingcenters, high-occupancybus stops and pullouts, vehicle turnarou(HOV)nds, andpark transitand facilities.ride lots, HOV HOVlanes, and andtransit commuter facilitiesrail includefacilities. transitThe objectives centers, busfor thestops HOVand andpullouts,transit turnarounds,facilities are: park and ride lots, HOV lanes, and commuter rail facilities. The• Improve objectivesthe capability for the HOVof the andterminal transitto facilitiesmove more are:people by increasing the number of • peopleImproveper vehicle.the capability of the terminal to move more people by increasing the • Providenumbertravel of peopletime savings per vehicle.and a more reliable trip time to HOV lane users. •• ProvideProvidetravel traveloptions time forsavingsHOVs andand aindividuals more reliablewithout tripadversely time to HOVaffecting lanethe users.general- • purposeProvidelanes. travel options for HOVs and individuals without adversely affecting the • Providegeneral-integrated purposeconnections lanes. for riders between