No abstract

Intelligent speed adaptation (ISA) systems are in-vehicle systems that have the capability of either warning drivers of adverse speeding behaviours or limiting them from exceeding a prevailing speed limit or advisory. The former, called the warning-informational ISA system, has been noted to be ineffective in reducing speeding while being acceptable to drivers. However, the limiting ISA system, called the mandatory ISA system, has been effective in reducing speeds, yet highly unacceptable from research conducted largely in Europe. These tests of ISA systems have shown that there is a significant consumer acceptance hurdle on the one hand, and an efficacy hurdle on the other. This paper presents the results of a driving simulator experiment that tested the acceptance and effectiveness of a new type of ISA system, called the advanced vehicular speed adaptation system (AVSAS). AVSAS was designed as a speed-management system, rather than a speed-limiting system, based on individual driver speeding behaviours under different roadway scenarios. Statistical analyses were conducted to determine the effectiveness of AVSAS while a survey was used to gauge the acceptance of the system. The results showed that AVSAS contributed to the reductions in the drivers' speeds for two roadway scenarios. The survey results revealed a higher acceptance rating of AVSAS.

One of the goals of local transportation agencies is to improve the quality of life for citizens and visitors by ensuring the efficient and safe movement of people and goods through the roadway system. Maintenance and rehabilitation of pavements are necessary to ensure that roadway networks continue to perform at their optimum. Currently, maintenance and rehabilitation of roadway networks depend on several factors including pavement condition indices, funding availability, among others. Previous studies have established relationships between crash frequency and pavement condition indices. However, the combined influence of speed, volume, and crash frequency on pavement indices, and thereby pavement management efforts has not been thoroughly examined. In this paper, a multinomial logistic regression was employed for 193 arterial segments to establish a new categorical variable: Composite Safety Index (CSI). The CSI values or ratings were based on pavement indices, crash frequency, traffic volumes and vehicular speeds to help categorize pavement sections for either maintenance or rehabilitation. The results indicated that the selected independent variables were statistically reliable in ranking pavement sections for rehabilitation or maintenance based on their CSI values.

The wait time of bus patrons at bus stops is one of several measures for assessing reliability of transit services, especially in urban areas. The uncertainty associated with waiting affects bus patrons' perception of quality of the service provided. Studies in this subject area have therefore been of interest to transit service agencies and officials. This paper presents the findings of a study conducted to determine patrons' maximum acceptable wait times (beyond the scheduled arrival time) at bus stops in an urban area. In all, 3387 bus patrons at 71 selected bus stops were surveyed over a period of 9 months. The results of the survey showed that the least acceptable wait time beyond the scheduled arrival time was 1 minute, while the maximum acceptable wait time was reported to be 20 minutes. Also, only one-third (33%) of the total number of patrons surveyed were willing to wait up to 5 minutes beyond the scheduled arrival time of buses. In addition, patrons are willing to wait longer in warm weather. On average, white patrons were found to have the least maximum acceptable wait times, followed by Hispanics, Asians, and then Blacks.