Database design usually takes the form of a schema, which formally describes the database structure, including the tables, their relationships, and constraints on data value types and lengths. Rather than defining an implementable schema, this chapter presents example tables that can store inform
The Project L02 Guide to Establishing Monitoring Programs for Travel Time Reliability describes how to develop and use a Travel Time Reliability Monitoring System (TTRMS). The guide also explains why such a system is useful; how it helps agencies do a better job of managing network performance; a
This supplement augments Chapter 3 by providing additional details about how to analyze travel time reliability for segments, routes, and networks.
Related Artifacts: L02 - Supplement A - Monitoring System Architecture; L02 - Supplement B - Methodological Details; L02 - Supple
This paper aims to establish a point-queue based end-to-end travel time prediction method on a corridor with multiple merges and diverges. In a point-queue model, a link can be considered as two segments: the free-flow segment and the queuing segment. The accompanying spreadsheet and presentation
This white paper describes an acceptable process for creating distributions of travel times for a route from distributions of the segments that compose said route. It has long been generally accepted by experts in traffic flow analysis, including statisticians, that the variability of travel time
The objective of this project is to develop system designs for programs to monitor travel time reliability and to prepare a guidebook that practitioners and others can use to design, build, operate, and maintain such systems. This document presents the amplified work plan for the project.
This paper examines a way to synthesize route travel time probability density functions (PDFs) on the basis of segment-level PDFs. Real-world data from I-5 in Sacramento, California, are employed. The first finding is that careful filtering is required to extract useful travel times from the raw
A list of work products from SHRP 2 L02 that could be tested as part of L38. The list is organized on the basis of the nominal sequence in which the work products is or could be used in a travel time reliability monitoring system or project.
This brief three-page document provides an overview of the purpose, methodology, and deliverables of the SHRP2-L02 Project. Project L02 was conducted to create methods by which travel time reliability can be monitored, assessed, and communicated to end users of the transportation system. The proj
This document shows how the Travel Time Reliability Monitoring System (TTRMS) can be used to address questions about network reliability.
Related Artifacts: L02 - Supplement A - Monitoring System Architecture; L02 - Supplement B - Methodological Details; L02 - Supplement C - C
This presentation on Project L02 was done at the Project L38 Preliminary Meeting on August 1, 2012. It provides an overview of the main Project L02 products, especially on the guidebook that describes how to develop a travel time reliability monitoring system (TTRMS).
Presentation for SHRP 2 Joint Technical Coordinating Committee Meeting
An overview of project L02 and its findings.
This technical presentation includes instructions with screenshots for using the SHRP2-L02 Corridor-Level Queue Prediction Model ("Point Queue Model"). Based on a set of analytic equations, the model was developed to calculate the number of queued vehicles ahead of the probe vehicle and to captur
Within the second Strategic Highway Research Program (SHRP 2), Project L02 focused on creating a suite of methods by which transportation agencies could monitor and evaluate travel time reliability. Creation of the methods also produced an improved understanding of why and how travel times vary a
As part of the SHRP 2 program, project L02 focuses on measuring, monitoring, and recording travel time reliability (TTR) information. Through its guidebook, case studies, and demonstration software the project will help operating agencies develop systems – hardware, software, and strategies – tha
This handbook, titled "Handbook for Communicating Travel Time Reliability Through Graphics and Tables", offers numerous ideas on how to communicate reliability information in graphical and tabular form.
It describes the display options listed in Table 1 in page 4. The table shows the au
Amplified Research Plan - SHRP2-L03
This diagram corresponds to Figure ES.2. in the SHRP2 report titled "Analytical Procedures for Determining the Impacts of Reliability Mitigation Strategies". It illustrates how several data sources came together as part of the SHRP2-L03 project. The Archive includes this very large L03 data set,
This presentation by Project L03 Principal Investigator Richard Margiotta to ITS Georgia on October 5, 2009 provides an overview of defining, measuring, and predicting reliability. The presentation ties into Project L03, which was ongoing at the time.
A webinar presentation on project L03 processes and findings.
An overview of project L03's process and findings.
An at-a-glance overview of the L03 Project.
The fundamental objective of SHRP 2 Project L03 was to develop predictive relationships between highway improvements and travel time reliability. In other words, how can the effect of an improvement on reliability be predicted? Alternatively, how can reliability be characterized as a function of
The Trajectory Processor is an essential part of the analytical framework developed under the SHRP2 L04 project to produce travel time reliability performance measures from planning and simulation model outputs. It calculates and visualizes travel time distributions and ssociated reliability indi
