Quantifying Cross-Weave Impact on Capacity Reduction for Freeway Facilities with Managed Lanes

2012 ◽  
Vol 2278 (1) ◽  
pp. 171-179 ◽  
Author(s):  
Xiaoyue Cathy Liu ◽  
Yinhai Wang ◽  
Bastian J. Schroeder ◽  
Nagui M. Rouphail
Keyword(s):  
Managed Lanes ◽  
Capacity Reduction

FIRE RESISTACE OF SHEAR CONNECTORS FOR COMPOSITE BEAMS

2020 ◽  
Vol 92 (6) ◽  
pp. 59-65
Author(s):  
G.P. TONKIH ◽  
◽  
D.A. CHESNOKOV ◽  
◽  
Keyword(s):  
Fire Resistance ◽  
Composite Structure ◽  
Composite Structures ◽  
Composite Beams ◽  
Design Codes ◽  
Connection Strength ◽  
Shear Connectors ◽  
Shear Connection ◽  
Capacity Reduction ◽  
Russian Research

Most of Russian research about composite structure fire resistance are dedicated to the composite slab behavior. The composite beams fire resistance had been never investigated in enough volume: the temperature evaluation within the scope of the actual Russian design codes leads to the significant reduction in the shear connection strength. Meanwhile, there no correlation between the strength decreasing and type of the shear connection. The article provides an overview of the relevant researches and offers some approaches which could take into account bearing capacity reduction of the shear connectors within composite structures design.

THE SUPPORT BONDS RIGIDITY INFLUENCES ON THE CARRYING CAPACITY REDUCTION OF THE SHALLOW SHELLS ON A RECTANGULAR PLAN

2020 ◽  
Vol 92 (6) ◽  
pp. 3-12
Author(s):  
A.G. KOLESNIKOV ◽  
Keyword(s):  
Variable Thickness ◽  
Carrying Capacity ◽  
Geometric Nonlinearity ◽  
Progressive Collapse ◽  
Geometrically Nonlinear ◽  
Loss Of Stability ◽  
Shallow Shells ◽  
Capacity Reduction ◽  
Internal Forces ◽  
Hinged Support

Geometric nonlinearity shallow shells on a square and rectangular plan with constant and variable thickness are considered. Loss of stability of a structure due to a decrease in the rigidity of one of the support (transition from fixed support to hinged support) is considered. The Bubnov-Galerkin method is used to solve differential equations of shallow geometrically nonlinear shells. The Vlasov's beam functions are used for approximating. The use of dimensionless quantities makes it possible to repeat the calculations and obtain similar dependences. The graphs are given that make it possible to assess the reduction in the critical load in the shell at each stage of reducing the rigidity of the support and to predict the further behavior of the structure. Regularities of changes in internal forces for various types of structure support are shown. Conclusions are made about the necessary design solutions to prevent the progressive collapse of the shell due to a decrease in the rigidity of one of the supports.

Capacity Reduction at Incidents

2008 ◽  
Vol 2071 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Victor L. Knoop ◽  
Serge P. Hoogendoorn ◽  
Henk J. van Zuylen
Keyword(s):  
Capacity Reduction

Safety Impact of Weaving Distance on Freeway Facilities with Managed Lanes using Both Microscopic Traffic and Driving Simulations

2018 ◽  
Vol 2672 (39) ◽  
pp. 130-141 ◽  
Author(s):  
Qing Cai ◽  
Moatz Saad ◽  
Mohamed Abdel-Aty ◽  
Jinghui Yuan ◽  
Jaeyoung Lee
Keyword(s):  
Traffic Safety ◽  
Traffic Congestion ◽  
Driving Simulator ◽  
Negative Impact ◽  
Control Strategies ◽  
General Purpose ◽  
Valuable Insight ◽  
Lane Change ◽  
Simulation Studies ◽  
Managed Lanes

With the challenges of increasing traffic congestion, the concept of managed lanes (MLs) has been gaining popularity recently as a means to effectively improve traffic mobility. MLs are usually designed to be left-lane concurrent with an at-grade access/exit. Such a design forms weaving segments since it requires vehicles to change multiple general purpose lanes (GPLs) to enter or exit the ML. The weaving segments could have a negative impact on traffic safety in the GPLs. This study provides a comprehensive investigation of the safety impact of different lengths for each lane change maneuver on GPL weaving segments close to the ingress and egress of MLs through two simulation approaches: VISSIM microsimulation and driving simulator. The two simulation studies are developed based on traffic data collected from freeway I-95 in Miami, Florida. The results from the two simulation studies support each other. Based on the two simulation studies, it is recommended that 1,000 feet be used as the optimal length for per lane change at the GPLs weaving segments with MLs. The safety impact of traffic volume, variable speed limit control strategies, and drivers’ gender and age characteristics are also explored. This study can provide valuable insight for evaluating the traffic performance of freeway weaving segments with the presence of concurrent GPLs and MLs in a highway safety context. It also provides guidelines for future conversion of freeways to include MLs.

Technological and Human Factor Considerations for Priced Managed Lane Traveler Information Systems

2018 ◽  
Vol 2672 (14) ◽  
pp. 10-19
Author(s):  
Nicholas S. Wood ◽  
Chris Simek ◽  
Susan T. Chrysler ◽  
Jeff Kaufman ◽  
Shawn Turner ◽  
...  
Keyword(s):  
Information Systems ◽  
Third Party ◽  
Managed Lanes ◽  
Trip Planning ◽  
Traveler Information ◽  
Traffic Incidents ◽  
Traveler Information Systems ◽  
National Review ◽  
Online Availability ◽  
Lane Closures

Travelers have many unique informational requirements to be able to navigate priced managed lanes. These demands often relate to specific managed lane features (e.g., access points, toll price) in addition to information about major traffic incidents and lane closures. Accommodating these needs with traditional roadway signage is a particular challenge given concerns about overloading and distracting drivers. This paper summarizes an investigation into traveler information systems for managed lanes, by considering a national review of current agency practices, a traveler survey, and an assessment for integrating advancing technologies. The national review found that many agencies vary considerably in pricing structure, number, and placement of priced destination points, and online availability of real-time toll information. A travel survey of 866 Texas-based respondents indicated that drivers prioritize information about traffic incidents and lane closures over toll price data (94% and 88% versus 41%, respectively). A higher share of respondents wanted to see travel time and incident alerts on in-vehicle devices, compared with a more statistically significant desire for destination and toll rate information on roadway signs. Most respondents use smartphone applications and mapping websites for pre-trip planning purposes (79% and 65%, respectively) compared with TV and radio reports (13%). Comparatively, prior research published 5 years earlier found that radio was a highly influential media in influencing behavior. This paper suggests a pathway for agencies to adopt a flexible approach for sharing essential data with third-party entities, based on the general transit-feed specification used for transit.

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