Pavement

Low Speed Collison Dynamics And Control: Year One Report

Tongue, Benson H.
Moon, Ahrie
1995

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....

Virtual Weigh Stations in California: A Preliminary Cost-Effectiveness Analysis

Santero, Nicholas
Nokes, William
Harvey, John
2005

A new technology known as Virtual Weigh Stations (VWS) is intended to transform data-collecting weigh-in-motion (WIM) sites to weight enforcement mechanisms. This study investigates the possible benefits to the highway pavements in California from potential use of VWS. The investigation proceeded in two steps: (1) determining the damage currently caused by overweight trucks and (2) modeling the potential pavement life saved with VWS. The data used for analysis is from the California Department of Transportation (Caltrans) WIM database.

Automatic Steering For Conventional Truck Trailers: Development and Assessment of Operating Concepts for Improving Safety, Productivity and Pavement Durability

Tsao, H.-S. Jacob
Dessouky, Yasser
Rangavajhula, Krishna
Zeta, Joseph Benjamin
Zhou, Lihong
2006

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-...

Evaluation of Wet Weather Accident Causation Criteria

Oh, Soon Mi, MS
Ragland, David R., PhD
Chan, Ching-Yao, PhD
2010

This report documents findings from analysis of traffic collision data from sites that display high collision rates only under wet pavement conditions. These sites were selected using Caltrans safety engineers’ field reports, Wet Table C “investigation required” locations, and a new approach called Continuous Risk Profile (CRP).The geometric features at the sites were studied via field visits and review of as-built plans. Rapid spatial changes (i.e., vertical and horizontal curve in short distance), narrower lane width, lack of median, and wider total freeway width were some of the notable...

Establishing Infrastructure Requirements for Bus Rapid Transportation Operations in Dedicated Bus Lanes

Monismith, Carl L., P.E.
Weissman, Shmuel L., PhD
Popescu, Lorina
Santero, Nicholas J.
2008

Bus Rapid Transit (BRT) has the potential to improve mass transit service and contribute to reduced traffic congestion in urban areas. To achieve this improvement in service BRT will require the use of dedicated bus lanes together with lane assist and precision docking (LA/PD) to accelerate the passenger boarding process. Using this approach, BRT lanes can be reduced somewhat in width. However, such a reduction will result in increased channelization of traffic which in turn can lead to a more rapid development of pavement distress. With today’s improved pavement engineering technology, it...

Travel Time Estimation on the San Francisco Bay Area Network Using Cellular Phones as Probes

Ygnace, Jean-Luc
Drane, Chris
Yim, Y. B.
de Lacvivier, Renaud
2000

Current traffic travel time estimates are largely based on road sensors embedded in the pavement. Today technical developments in cellular positioning and the spread of wireless phones provide the opportunity to track cell phone equipped drivers as traffic probes. The Federal Communication Commission Phase II mandate for Enhanced-911 (E-911) requires that wireless carriers must provide the location of a 911 wireless call by October 1, 2001 to the Public Safety Answering Point (PSAP), within approximately 125 meters, or under one-tenth of a mile in the majority of situations. The motivation...

Investigation Of An Optical Method To Determine The Presence Of Ice On Road Surfaces

Misener, James
1998

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.

Mapping and Improving the Delivery Process of Highway Pavement Rehabilitation Projects

Tommelein, Iris D.
Blampied, Nigel
2018

Highway pavement rehabilitation (HPR) is a service provided by departments of transportation (DOTs) worldwide. The process of delivering HPR projects involves not only a transportation department but also many other project participants and stakeholders; furthermore, it is subject to numerous technical- as well as socio-political considerations. Interestingly—though not surprisingly—the processes DOTs use to deliver this service vary widely, not only between countries or between states in the US, but also regionally within a given state such as California. While some variation is to be...

What Can You Do with a County Road that You Can’t Afford to Maintain?

Jones, David
2017

Many rural county road networks were created at a time when funding was greater and rural populations were often larger than they are today. Eventually, surface treatments such as chip seals or thin asphalt were applied to many of these gravel roads to provide them with an all‐weather surface. These treated surfaces were also desirable because conventional gravel roads are dusty, often develop wash boarding quickly, and have high rates of gravel loss—which result in unsafe and uncomfortable conditions and greater damage to vehicles and crops. A solution to this problem is called ‘unpaving...

Unintended Impacts of Increased Truck Loads on Pavement Supply-Chain Emissions

Sathaye, Nakul
Horvath, Arpad
Madanat, Samer
2009

In recent years, the reduction of freight truck trips has been a common policy goal. To this end, policies aimed at influencing load consolidation, load factors and increasing maximum truck weight limits have been suggested and implemented, resulting in higher gross vehicle weights. The purpose of such policies has generally been to mitigate congestion and environmental impacts. However, trucks cause most of the damage incurred by pavements. The supply chain associated with pavement maintenance and construction releases significant air emissions, raising the question of whether increased...