Complete streets movement is a national effort to return to traditional streets in cities to enhance livability, safely, accommodate all modes of travel, provide travel choices, ease traffic congestion, and promote healthier communities. The California Department of Transportation (Caltrans) and several local agencies in the State have developed implementation plans for complete streets. In this project, the authors developed and tested improved strategies and analysis methodologies for complete streets, taking into consideration the emerging advances in technology on control devices and...
Transportation Research Record: Journal of the Transportation Research Board
2021
The Highway Capacity Manual (HCM) employs a simple five-point system to assess the quality of bikeway pavement as part of the comprehensive bicycle level of service (LOS) evaluation. Unfortunately, the ambiguous and rudimentary nature of the existing HCM Pavement Quality Index (PQI) fails to offer an objective review of bikeways across different jurisdictions. In the following analysis, first is an assessment of the PQI and bicycle LOS in the HCM. To demonstrate the impact of the pavement quality rating and the importance of a more standardized evaluation method, a sensitivity analysis is...
This report documents a review of the literature for commercial motor vehicle inspection and compliance stations and its relationship with the growth of truck travel over the next 25 years and the lack of concurrent capacity increases in staffing at such stations. Problems result in that more commercial vehicles will need to stop for inspection with longer queues at weigh stations associated with increased congestion, increased wait times, more idling trucks, and increased safety hazards. Alternatively, without stopping at inspection and compliance stations other problems will result such...
In studies undertaken by staff of the PATH Program concerned with automatic vehicle control (AVC) ceramic sensors (magnets) have been placed at or near the surface of both asphalt concrete (AC) and portland cement concrete (PCC) pavements. Thus far sensors have been installed at three locations: 1) AC pavement at the Richmond Field Station (RFS); 2) AC and PCC pavement on Interstate 15 in San Diego, CA; and 3) AC and PCC pavement on Interstate 80 near Donner Summit, CA. The installations at Donner Summit have been used for the guidance of snow plows during the winter months. With increased...
In this project we have accomplished three goals. First, we have merged two existing, complementary databases in an effort to produce a single database that lists all the railroad crossings, and their known properties, in the San Joaquin Rail Corridor (SJRC). Second, we have demonstrated the practicality of using video data gathered from an existing Locomotive Video Data Acquistion System (LVDAS) to search for crossing violations in order to populate a database of crossing violations, which we term “near-misses”. By this means, crossings that are particularly susceptible to violations,...
Work done under this "Innovative Proposal" may be summarized as follows. A closed-form series solution is provided for the displacement of a pavement loaded by a truck modeled as an Euler beam with elastic foundation under a moving load. A method is developed to estimate the load based on accelerometer measurements. Lastly, it was found that the measurement system that we built was not suited for the problem at hand because the accelerometer bandwidth was too high and the system could not isolate the accelerometer from ambient noise. This led to a new measurement system design. However,...
This report characterizes the statistical performance of the magnetic nails concept for estimating the positions of vehicles within their marked lanes. The report also presents a mathematical model for sensor noise due to the distortions of the earth field by regular patterns of ferrous reinforcing bars in the pavement.
This report discusses the issues investigated during the first phase of a project which focuses on the development of a simulation program which will allow the study of platoon dynamics in both nominal and emergency scenarios. Preliminary issues include collision detection between the vehicles within the platoon and determining the platoon's post-crash behavior. A two-dimensional vehicle has been developed to addresses these issues. The overall simulation program includes individual modules that supply control input force, aerodynamic drag force, and road-tire interaction forces....
This report presents a review of alternative techniques to determine the presence of ice on road surfaces. It examines techniques ranging from passive, in-pavement technologies, to different remote sensing techniques. The author presents the Polarized Reflectance Infrared Signature Method (PRISM) technique which uses differences in measured near infrared reflectance between ice, water and dry road due to absorption, in addition to the effect of polarization to discount the contribution of specutacular reflectance off the front surface.
Trucking productivity can be significantly increased by moving freight with longer combination vehicles (LCVs). However, LCV operations not only raise safety concerns for the surrounding traffic and the LCV drivers themselves but also can damage roadways and bridges not equipped to support the operations. All the discussion about truck size and weight limitations or about the pros and cons of LCV operations is predicated on the use of conventional tractors and trailers. We however observed that a root cause of several major issues associated with LCV operations is the problem of off-...
