Safety and capacity analysis of automated and manual highway systems

Abstract

The contents of this report reflect the views of the authors who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the State of California. This report does not constitute a standard, specification, or regulation.

Identification of new added value services on intelligent transportation systems

“…Many researches thought that using advanced technologies to improve highway capacity could provide an effective solution to increase and guarantee road safety (Rodier et al 1998, Sheu 2002, Giannopoulos 2004. A possible outgrowth of today's ITS technologies is the Automated Highway System (AHS), a concept that uses information and control technologies to create 'hands-off and feet-off' freeway driving (Carbaugh et al 1998). Studies from Chang (1997) into the possible benefits of applying communication and control technologies to our highways forced to get gains in safety and efficiency.…”

A stochastic approach for vehicle safety modeling in a platoon of vehicles equipped with vehicular communications

“…To account for it, the usual methodology is to evaluate deterministic models by applying a Monte Carlo or stochastic analysis over an extensive range of their parameters [5], [7]. We are interested in stochastic approaches, so in Table I we briefly describe the models proposed by Choi and Swaroop [8] and by Carbaugh et al [9], and compare them with our model. Though there are substantial differences, we have tried to faithfully reproduce their experiments, and the results obtained show a similar trend, as can be seen in Fig.…”

Advanced Driver Assistance Systems from Autonomous to Cooperative Approach

“…In a study by VanderWerf et al (2002b), efficiency impacts of ACC (0.5 s time gap) were simulated with the assumption that the system can brake with the maximum rate in emergency braking, which is much shorter than 1.1 s, generally used with manual driving (Carbaugh et al, 1998). Their simulation results show that the gain in capacity increases quadratically with the penetration level: the capacity would be doubled at 100% penetration.…”

“…Vehicle-vehicle communication was one of the technologies recommended for ACC to ensure string stability (Sheikholeslam and Desoer, 1990). With sensor-based systems, sensor delay can take up to 100 ms, but with a vehicle-vehicle communication-based system, communication delay is normally at a level of 20 ms (Carbaugh et al, 1998;Michael et al, 1998). Bareket et al (2003) studied the string stability impacts of sensor-based ACC using a combination of experiments, models and simulations.…”

“…With on-board sensors, a judgement of emergency deceleration of the preceding vehicle is based on filtering of the detected speed profile, thus response delay can take up to 0.3 s. With a vehicle-vehicle communication-based system, a clear message of emergency braking can be transmitted from the leading vehicle to its following vehicles, thus response delays can be reduced to a level of 0.1 s (Choi and Hedrick, 1995;Gerdes and Hedrick, 1995;Carbaugh et al, 1998;Michael et al, 1998).…”