When to Control the Ramps on Freeway Corridors? A Novel Stability-and-MFD-Based Approach

2014 ◽  
Vol 15 (6) ◽  
pp. 2572-2582 ◽  
Author(s):  
Huizhao Tu ◽  
Hao Li ◽  
Yibing Wang ◽  
Lijun Sun
Keyword(s):  
Freeway Corridors

scholarly journals Measuring Recurrent and Nonrecurrent Traffic Congestion

2003 ◽  
Vol 1856 (1) ◽  
pp. 118-124 ◽  
Author(s):  
Alexander Skabardonis ◽  
Pravin Varaiya ◽  
Karl F. Petty
Keyword(s):  
Los Angeles ◽  
Travel Time ◽  
San Francisco ◽  
Traffic Congestion ◽  
Real Life ◽  
Time Variability ◽  
Loop Detectors ◽  
Bay Area ◽  
Freeway Corridors ◽  
Travel Time Variability

A methodology and its application to measure total, recurrent, and nonrecurrent (incident related) delay on urban freeways are described. The methodology used data from loop detectors and calculated the average and the probability distribution of delays. Application of the methodology to two real-life freeway corridors in Los Angeles, California, and one in the San Francisco, California, Bay Area, indicated that reliable measurement of congestion also should provide measures of uncertainty in congestion. In the three applications, incident-related delay was found to be 13% to 30% of the total congestion delay during peak periods. The methodology also quantified the congestion impacts on travel time and travel time variability.

Optimum Volume of Freeway Corridors

2020 ◽  
Vol 2674 (3) ◽  
pp. 27-36
Author(s):  
Siavash Shojaat ◽  
Justin Geistefeldt ◽  
Brian Wolshon
Keyword(s):  
Quality Of Service ◽  
Real World ◽  
Flow Index ◽  
Traffic Demand ◽  
Probability Of Survival ◽  
Freeway Corridors ◽  
Freeway Corridor ◽  
Different Characteristics ◽  
Optimum Volume

Conventional methods to assess the quality of service on freeways are based on the comparison of a specific peak hour traffic demand to the capacity of the facility, which is usually measured at a single uniform bottleneck section. However, estimating the quality of service of one bottleneck section may not be sufficient to assess the performance of an entire freeway facility. A driver traveling along a freeway corridor may actually encounter multiple flow breakdowns at independent bottleneck sections, which affect the overall quality of service. This paper introduces a comprehensive approach that considers an entire freeway corridor as a system consisting of successive independent bottlenecks with different characteristics, and can be used to estimate the optimum sustainable volume. The methodology is based on the sustained flow index, which is defined as the product of traffic volume and the probability of survival at this volume. Optimum volumes of two real-world corridors are estimated based on the new derivations. The empirical results reveal that the optimum volume and the capacity of an entire corridor is less than those of its most restrictive bottleneck.

An Indicator for Determining the Control Timing of Ramp Metering on Urban Freeway Corridors

CICTP 2014 ◽  
2014 ◽  
Author(s):  
Zixiang Gao ◽  
Huizhao Tu ◽  
Yueming Ding ◽  
Zhenfei Li ◽  
Lijun Sun
Keyword(s):  
Ramp Metering ◽  
Freeway Corridors ◽  
Urban Freeway

Mobility and Energy Consumption Impacts of Cooperative Adaptive Cruise Control Vehicle Strings on Freeway Corridors

2020 ◽  
Vol 2674 (9) ◽  
pp. 111-123
Author(s):  
Hao Liu ◽  
Xiao-Yun Lu ◽  
Steven E. Shladover
Keyword(s):  
Energy Consumption ◽  
Fuel Economy ◽  
Adaptive Cruise Control ◽  
Baseline Scenario ◽  
Vehicle Speed ◽  
Market Penetration ◽  
Cruise Control ◽  
Cooperative Adaptive Cruise Control ◽  
Freeway Corridors ◽  
The Impact

Cooperative adaptive cruise control (CACC) vehicle string operations have the potential to improve significantly the mobility and energy consumption performance of congested freeway corridors. This study examines the impact of CACC string operations on vehicle speed and fuel economy on the 13-mi SR-99 corridor, near Sacramento, CA. It extends the existing body of knowledge by performing a multi-scenario simulation analysis of the freeway corridor. A simulation study evaluated the performance of the corridor under various CACC market penetration scenarios and traffic demand inputs. The CACC string operation was also analyzed when vehicle awareness device (VAD) and CACC managed lane (ML) strategies were implemented. The case study revealed that the average vehicle speed increased by 70% when the CACC market penetration increased from 0% to 100%. The highest average fuel economy, expressed in miles per gallon (mpg), was achieved under the 50% CACC scenario where mpg was 27. This was 10% higher than the baseline scenario. However, when the CACC market penetration was 50% or higher, the vehicle fuel efficiency only had minor increases. When CACC market penetration reached 100%, the corridor allowed 30% more traffic to enter the network without experiencing reduced average speed. Results also indicate that the VAD strategy increased the speed by 8% when the CACC market penetration was 20% or 40%, while there was a minor decrease in mpg. The ML strategy decreased the corridor performance when implemented alone.

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