viernes, 24 de septiembre de 2010

Alternative Intersection and Interchange Designs

Today's transportation professionals, with the limited resources available to them, are challenged to meet the mobility needs of an increasing population. At many highway junctions, congestion continues to worsen, and drivers, pedestrians and bicyclists experience increasing delays and heightened exposure to risk. Today's traffic volumes and travel demands often lead to safety problems that are too complex for conventional intersection designs to properly handle. Consequently, more engineers are considering various innovative treatments as they seek solutions to these complex problems.

The Alternative Intersections/Interchanges: Informational Report covers four intersection and two interchange designs that offer substantial advantages over conventional at-grade intersections and grade-separated diamond interchanges. It also provides information on each alternative treatment covering salient geometric design features, operational and safety issues, access management, costs, construction sequencing, environmental benefits and applicability. The four alternative intersection treatments covered in this report are displaced left-turn (DLT), restricted crossing U-turn (RCUT), median U-turn (MUT) and quadrant roadway (QR) intersections. In addition the two alternative interchange designs include double crossover diamond (DCD) and DLT interchanges. The report and corresponding Tech Briefs can be found on the Web as follows:

Alternative Intersections/Interchanges: Informational Report (AIIR)

Double Crossover Diamond Interchange (Tech Brief)

Displaced Left-Turn Intersection (Tech Brief)

Displaced Left-Turn Interchange (Tech Brief)

Median U-Turn Intersection (Tech Brief)

Quadrant Roadway Intersection (Tech Brief)

Restricted Crossing U-Turn Intersection (Tech Brief)


This article is extracted from ITE newsletter and ITE thank to
Mr. Lincoln Cobb and Mr. Ed Stollof for contributing these references.


FHWA Roundabouts and Mini Roundabouts Technical Summaries

This technical summary is designed as a reference for State and local transportation officials, Federal Highway Administration (FHWA) Division Safety Engineers, and other professionals involved in the design, selection, and implementation of roundabouts. Its purpose is to provide an overview of safety considerations in the design, implementation, and operation of roundabout intersections in urban, suburban, and rural environments where design considerations can vary as a function of land uses, travel speeds, volumes of traffic by mode (e.g., car, pedestrian, or bicycle), and many other variables.

This technical summary explores the characteristics of modern roundabouts while reinforcing the need to apply a principles-based approach to design. It provides readers with an overview of the key considerations for planning, analysis, and design of single-lane and multilane roundabouts. Section 1 of this document summarizes the characteristics of roundabouts. Section 2 presents benefits of roundabout intersections compared to traditional signalized and/or stop-controlled intersections. Sections 3-6 provide an overview of user, location, operational and design considerations respectively.

The information presented in this summary outlines the principles described in the FHWA document Roundabouts: An Informational Guide and the forthcoming 2nd Edition of that document (hereafter referred to as the Roundabout Guide), which is in progress at the time of this writing and due to be published in 2010. Specific considerations for mini-roundabouts are summarized in a separate FHWA document titled Mini- Roundabouts Technical Summary.

Please clic en the next link to see the information:

Roundabouts

http://safety.fhwa.dot.gov/intersection/roundabouts/fhwasa10006/

Mini- Roundabouts

http://safety.fhwa.dot.gov/intersection/roundabouts/fhwasa10007/

Regards

Gregorio



martes, 24 de agosto de 2010

FREE Designing for Pedestrian Safety Webinar Series.

The FHWA Safety Office and the Pedestrian and Bicycle Information Center (PBIC) will offer an 8-part Webinar series intended to help communities address pedestrian safety issues through design and engineering solutions. Modeled after the FHWA’s/PBIC’s in-person training course “Designing for Pedestrian Safety,” the free Webinars will cover topics ranging from sidewalk design to road diets.

Part 1: Introduction to Pedestrian Safety Design and Planning Principles
Presented by Craig Allred, FHWA Resource Center Technical Specialist and Michael Ronkin, Owner, Designing Streets for Pedestrians and Bicyclists, LLC.
Tuesday, July 20 at 2:30 p.m. EST
An archived recording, transcript, and additional resources from this Webinar will soon be available. Upcoming Webinars and archives of each past program can be accessed at www.walkinginfo.org/webinars.

Part 2: Sidewalk Design
Presented by Peter Eun, FHWA RC Safety Engineer
Tuesday, August 3 at 2:00 p.m. EST
Register at www2.gotomeeting.com/register/674641298

Part 3: Treatments at Unsignalized Pedestrian Crossings
Presented by Charlie Zegeer, PBIC Director
Tuesday, August 17 at 2:00 p.m. EST
Register at www2.gotomeeting.com/register/957730818

Part 4: Intersection Geometry
Presented by John LaPlante, Director of Traffic Engineering, T.Y. Lin International, Inc and Keith Sinclair, Acting Assistant Division Administrator, FHWA Connecticut Division
Thursday, September 9 at 2:00 p.m. EST
Register at www2.gotomeeting.com/register/479167939

Part 5: Signalized Intersections
Presented by Michael Moule, President, Livable Streets, Inc.
and Fred Ranck, FHWA Resource Center Safety Design Engineer
Monday, September 27 at 2:00 p.m. EST
Register at www2.gotomeeting.com/register/619931450

Part 6: Interchanges and Roundabouts
Presented by Fred Ranck, FHWA Resource Center Safety Design Engineer
and Hillary Isebrands, FHWA Resource Center Safety Specialist
Tuesday, October 5 at 2:00 p.m. EST
Register at www2.gotomeeting.com/register/460531066

Part 7: Pedestrians and Transit
Presented by Dan Nabors, Senior Transportation Engineer, VHB Date TBD

Part 8: Road Diets
Presented by Peter Lagerwey, Senior Planner, Toole Design Group
Date TBD

To register for upcoming Webinars and find out about future Webinar dates as they are released, please visit www.walkinginfo.org/webinars.

Content from the PBIC Designing for Pedestrian Safety Webinar series is drawn from the PBIC’s in-person training focused on engineering solutions for pedestrian safety. The training is meant for engineers, planners, traffic safety and enforcement professionals, public health and injury prevention professionals, and decision-makers who are seeking ideas and solutions for making changes to the physical environment that improve safety for pedestrians. Detailed information on this and other training opportunities offered by PBIC can be found at www.walkinginfo.org/training.

Since its inception in 1999, PBIC's mission has been to improve the quality of life in communities through the increase of safe walking and bicycling as a viable means of transportation and physical activity. The Pedestrian and Bicycle Information Center is maintained by the University of North Carolina Highway Safety Research Center with funding from the U.S. Department of Transportation Federal Highway Administration.