TY - JOUR
T1 - Capacity and safety analysis of hard-shoulder running (HSR). A motorway case study
AU - Guerrieri, Marco
AU - Guerrieri, Marco
AU - Mauro, Raffaele
PY - 2016
Y1 - 2016
N2 - Operational motorway conditions can be improved by introducing traffic flow management and control systems, such as ramp metering (RM), high occupancy vehicle (HOV) lanes, real-time variable speed limits (VSLs), reversible lanes (RL), automated highway systems (AHS) and hard-shoulder running (HSR). The effects of such devices need to be examined in terms of capacity and safety. This paper examines the case study of the Italian motorway A22, which is supposed to be equipped with an HSR system implemented along 128 km in order to reduce congestion with consequent improvement in levels of service (LOS). We studied the traffic processes (capacity, flow distribution between lanes, reliability, etc.) and estimated the expected capacity and safety conditions. These latter were studied with the method provided by the Highway Safety Manual (HSM), as well as by undertaking sensitivity analyses to quantify the expected changes in crash frequency at varying HSR activation hours (from 30 to 200 h) in a year. It has been observed that HSR activation does not involve significant variations in the general safety conditions in the presence of a considerable capacity increase up to 35%. Moreover, have been identified the cases which require speed limit implementation (with VSLs system) in function of the values of reliability ϕ and velocity process V‾, and also suggested a speed limit sign system.
AB - Operational motorway conditions can be improved by introducing traffic flow management and control systems, such as ramp metering (RM), high occupancy vehicle (HOV) lanes, real-time variable speed limits (VSLs), reversible lanes (RL), automated highway systems (AHS) and hard-shoulder running (HSR). The effects of such devices need to be examined in terms of capacity and safety. This paper examines the case study of the Italian motorway A22, which is supposed to be equipped with an HSR system implemented along 128 km in order to reduce congestion with consequent improvement in levels of service (LOS). We studied the traffic processes (capacity, flow distribution between lanes, reliability, etc.) and estimated the expected capacity and safety conditions. These latter were studied with the method provided by the Highway Safety Manual (HSM), as well as by undertaking sensitivity analyses to quantify the expected changes in crash frequency at varying HSR activation hours (from 30 to 200 h) in a year. It has been observed that HSR activation does not involve significant variations in the general safety conditions in the presence of a considerable capacity increase up to 35%. Moreover, have been identified the cases which require speed limit implementation (with VSLs system) in function of the values of reliability ϕ and velocity process V‾, and also suggested a speed limit sign system.
KW - Capacity
KW - Civil and Structural Engineering
KW - HSM
KW - Hard-shoulder running
KW - Management Science and Operations Research
KW - Reliability
KW - Safety
KW - Transportation
KW - Variable speed limit
KW - Capacity
KW - Civil and Structural Engineering
KW - HSM
KW - Hard-shoulder running
KW - Management Science and Operations Research
KW - Reliability
KW - Safety
KW - Transportation
KW - Variable speed limit
UR - http://hdl.handle.net/10447/236789
UR - http://www.elsevier.com/inca/publications/store/5/4/7/
M3 - Article
VL - 92
SP - 162
EP - 183
JO - Transportation Research, Part A: Policy and Practice
JF - Transportation Research, Part A: Policy and Practice
SN - 0965-8564
ER -