Adam Kirk

Crash rates and traffic maneuvers of younger drivers

Although the population of younger drivers has decreased over recent decades, their crash rates have increased. Research has associated their higher crash rates with societal influences and youthful behavior. Research was conducted to identify the specific driving maneuvers of which unsuccessful undertaking results in specific types of crashes involving younger drivers. Four types of crashes were identified as the most prominent for young drivers: intersection, rear end, passing, and single vehicle. The analysis was performed by examining the Kentucky crash database for the 1994-1996 period by using the quasi-induced exposure method. The results showed that for all crashes, there is a general trend of decreasing involvement with increasing age, which indicates that these drivers’ inexperience is the largest single contributor to their increased crash rates. Of significance is that for all crashes, a dramatic decrease of involvement after the first year of driving between the ages of 16 and 17 is observed. This may be indicative of a steep learning curve in the first years of driving regarding the ability to control a vehicle. Therefore, little can be done to improve this phenomenon. Increasing awareness among young drivers about these issues and their likely crash involvement appears to be the only viable approach. However, preliminary efforts from the graduated license program show that some trends have been reduced, indicating a possible influence on the crash rates of young drivers.

Improving Intersection Design Practices

This study aims to use operational characteristics to help determine the size and the design of intersections on the basis of a targeted level of operation. This approach will allow for a preliminary evaluation of a broader range of possible designs, by screening out those designs considered less desirable or inappropriate on the basis of operational performance. This approach will also allow for a more objective comparison of all alternatives because all options target the same operational service level. The use of the critical lane analysis method was considered an appropriate approach for developing such size estimates for intersections. Similar methods for stop-controlled and yield-controlled intersections were also identified because it was necessary to expand these methods to include unsignalized designs as well. The Intersection Design Alternative Tool developed through this effort is capable of evaluating 13 intersection alternatives and identifying preferred lane configurations from more than 12,000 available configurations.

Practical Solution Concepts for Planning and Designing Roadways

Developing a procedure that yields up to the maximum margin of return for the investment requires an approach that takes into account specific safety issues and the commensurate design elements for each roadway. Kentucky’s highway agency has embarked upon an initiative tagged “practical solutions” which sets its goal toward reducing costs throughout the project development process extended into operations and maintenance of all highway facilities. This operationally defines a design procedure within the context of practical solutions and sets up the guiding principles of the approach. The most critical component of practical solutions in planning and design is the definition and clarification of the initial project concept (its specific goals and objectives) since it is the corner stone of the project and used to significantly contain the cost and impact of a project. Traditional design tends to seek as high a design speed as reasonable with the aim to reduce travel time. Practical design requires that le...

QUANTIFICATION OF THE BENEFITS OF ACCESS MANAGEMENT FOR KENTUCKY

This report describes the benefits quantification performed for the proposed access management plan for Kentucky. This study evaluates the capacity, safety and economic impacts associated with access management programs. The proposed Kentucky access management program will seek to standardize driveway and traffic signal spacing on all state maintained roadways in the state. The Transportation Research Board (TRB) Access Impact Calculator developed as a part of NCHRP Report 420, was used to evaluate the potential benefits of the proposed plan on a sample of Kentucky roadways. The results of this analysis were then extrapolated to the statewide system to estimate total annual savings in delay and crash reductions. Based upon this analysis, it is estimated that the proposed access management plan could save Kentucky road users approximately 950 million dollars per year.

Functional Classification System to Aid Contextual Design

A proposed functional classification system has been developed to address context and multimodal accommodation of the existing classification system. The proposed functional classification system is intended to facilitate optimal geometric design solutions while accounting for context, user needs, and functions. The new classification system communicates improved information to the designer so that balanced designs can be achieved through documented prioritization of roadway users. The proposed functional classification system identifies user groups, which include drivers, pedestrians, and bicyclists. Fundamental design elements for each mode are identified, and design ranges for each are provided according to the overall roadway network type. The correlation results of context, roadway types, and users are displayed in the expanded functional classification system matrix, allowing for the development of a multimodal, context-based design with some degree of flexibility. Each matrix cell defines the various users (drivers, bicyclists, and pedestrians) and identifies those characteristics to be balanced.

Estimating Earthwork Volumes Through Use of Unmanned Aerial Systems

Unmanned aerial systems (UASs) and unmanned aerial vehicles (UAVs) have become increasingly attractive for numerous surveying applications in civil engineering, agriculture, and many other fields. The unmanned systems and vehicles are capable of performing photogrammetric data acquisition with equipped digital cameras that allows for converting images to highly precise, georeferenced three-dimensional models. However, more studies are needed to demonstrate practical applications of UAS systems and UAVs on construction sites. In this project, UAS systems and UAVs and digital photogrammetry technology are introduced to estimate the earthwork volume of a highway extension project. The georeferenced images were processed by the photogrammetry software, Pix4Dmapper, which is a tool for converting images into an accurate and applicable three-dimensional point cloud model. Progress models were created over the course of several weeks. The volume of earth was computed by comparing the point cloud of the progress models after model processing. To ensure reliability, the accuracy of the UAS and UAV photogrammetry was verified by comparison with conventional ground survey methods and the results from different flights. The project presents the feasibility and effectiveness of using UAS systems and UAVs in estimating earthwork volumes on the basis of the results of an accuracy test and the efficiency of the survey.

Safety-Based Left-Turn Phasing Decisions for Signalized Intersections

The efficient and safe movement of traffic at signalized intersections is the primary objective of any signal-phasing and signal-timing plan. Accommodation of left turns is more critical because of the higher need for balancing operations and safety. The objective of this study was to develop models to estimate the safety effects of the use of left-turn phasing schemes. The models were based on data from 200 intersections in urban areas in Kentucky. For each intersection, approaches with a left-turn lane were isolated and considered with their opposing through approach to examine the left-turn–related crashes. This combination of movements was considered to be one of the most dangerous in intersection safety. Hourly traffic volumes and crash data were used in the modeling approach, along with the geometry of the intersection. The models allowed for the determination of the most effective type of left-turn signalization that was based on the specific characteristics of an intersection approach. The accompanying nomographs provide an improvement over existing methods and warrants and allow for a systematic and quick evaluation of the left-turn phase to be selected. The models used the most common variables that were already known during the design phase, and they could be used to determine whether a permitted or protected-only phase would suit the intersection when safety performance was considered.

An optimization tool for intesction design

Intersection design is a balancing act of various elements and constraints to produce a solution that will address mobility, safety, environment, and financial aspects of the project. To achieve this balance, alternative strategies and options must be identified, developed and evaluated in a systematic manner. Shrinking state transportation budgets require the development of designs and solutions that are more efficient and practical in addressing project needs. An optimization tool has been developed that is capable of evaluating several alternative traffic control and intersection designs for a given location. This tool incorporates safety, capacity, cost and non-motorized transportation criteria to determine an optimum design.

Improving Intersection Design Practices, Final Report - Phase I

The purpose of this report is to document the development of the Intersection Design Alternative Tool (IDAT) developed for the Kentucky Transportation Cabinet. IDAT provides an automated objective design and evaluation approach of 14 alternative intersection designs to assist in the conceptual design of at-grade intersections. The tool evaluates intersection operations, safety performance, bicycle/pedestrian accommodation; and has the ability to assist access management implementation.

A Process for Measuring Context Sensitive Solutions Benefits

Context Sensitive Solutions (CSS) provides a systematic and comprehensive approach to project development from inception and planning through operations and maintenance. The ability to categorize and measure the benefits of CSS projects is vital to the long-term success of this approach. The paper presents a framework for transportation officials and professionals that allows for the comprehensive quantification of benefits resulting from CSS through all phases of project development. A fundamental aspect of this framework is the identification of CSS action principles and their potential benefits. A matrix that correlates benefits to specific CSS principles was generated to allow for the development of appropriate metric indicators for each benefit. Guidelines for benefit analysis have been developed to provide transportation agencies with a set of recommended practices for assessing benefits. The guidelines emphasize the fact that CSS is a principle-driven, benefit-justified effort that can enhance an agency’s goals and interaction with stakeholders and the public. The need exists to analyze and measure the benefits of CSS and its impact on projects (e.g. cost and delay) in order to demonstrate a best use of agency resources.