CARS-Delay Concept of Operations Functional Requirements System
Total Page:16
File Type:pdf, Size:1020Kb
CARS-Delay Concept of Operations Functional Requirements System Design Prepared by: Castle Rock Associates Prepared for: Minnesota Department of Transportation Last Revision: June 30, 2015 Document Version History Version Author Date Change Notes 1 pd 6/29/2014 Initial draft for Idaho. 2 pd 7/14/2014 Reviewed with Dane and Sam 3 fc 8/1/2014 Added background ideas to first draft. 4 kv 8/18/2014 Reviewing initial draft. 5 pd 8/19/2014 Merging separate content for initial Iowa meeting. 6 pd 9/14/2014 Added Iowa and Minnesota inputs. 7 pd 10/30/2014 Reflecting agreed priorities and phasing. 8 pd 11/8/2014 Added many use cases from real data. 9 pd 12/6/2014 Started “build” version for Mn/DOT Innovative Ideas 10 pd 12/16/2014 Continuing “build” version for Minnesota and Idaho. 11 pd 1/7/2015 Further work on “build” version for all three states. 12 pd 1/27/2015 Build version for ITD and Mn/DOT Innovative Ideas. 13 pd 2/7/2015 San Diego corridor delays and travel times added. 14 pd 2/16/2015 Minor changes after review with developers. 15 pd 2/18/2015 Changes during and after Iowa meeting of 2/17/15. 16 pd 2/24/2015 Changes during Boise meeting of 2/24/2015 17 pd Changes during Minnesota meeting 18m du 6/30/15 Updated for MnDOT final submission 2 Final CARS-Delay_SystemDesign_18m_du.docx Confidential. Limited Circulation Document. Listed Agencies Only Table of Contents 1. Concept of Operations ................................................................................................................................. 5 2. Functional Requirements .............................................................................................................................. 9 2.1 Overview .................................................................................................................................................. 9 2.2 Approach ................................................................................................................................................ 10 2.2.1 Included route designators and sections ................................................................................................ 10 2.2.2 Included event phrases (CARS-Delay MU) ....................................................................................... 11 2.2.3 Included event priorities (CARS-Delay MU) ..................................................................................... 12 2.2.4 Included times of day (CARS-Delay MU and SD) ........................................................................... 12 2.3 Delay Assessment ................................................................................................................................. 13 2.3.1 CARS-Delay MU ............................................................................................................................ 13 2.3.2 Event list (CARS-Delay MU) .......................................................................................................... 13 2.3.3 New and edited reports ....................................................................................................................... 15 2.3.4 Events not currently being monitored for delay (CARS-Delay MU) .................................................... 15 2.3.5 CARS-Delay SD ............................................................................................................................. 15 2.4 Announcing Delays (CARS-Delay MU) ............................................................................................ 16 3. CARS-Delay System Design ...................................................................................................................... 16 3.1 CARS-Delay MU Approach ................................................................................................................ 17 3.1.1 Delay prediction ................................................................................................................................. 18 3.1.2 Sticking to the monitored road—use of intermediate waypoints ............................................................ 21 3.2 Roadways to monitor ........................................................................................................................... 23 3.2.1 Minnesota’s suggested CD1 highways ................................................................................................. 24 3.3 Phrases to be included .......................................................................................................................... 26 3.3.1 Accident/incident phrases ................................................................................................................... 26 3.3.2 Roadwork phrases .............................................................................................................................. 27 3.3.3 Lane blockage/closure phrases ............................................................................................................ 27 3.3.4 Traffic conditions phrases .................................................................................................................... 28 3.4 Grouping events .................................................................................................................................... 28 3.5 Find delay start and end coordinates ................................................................................................. 28 3.6 Directions API ...................................................................................................................................... 31 3.6.1 Efficient design ................................................................................................................................... 31 3.6.2 Shared delay license ............................................................................................................................ 32 3 Final CARS-Delay_SystemDesign_18m_du.docx Confidential. Limited Circulation Document. Listed Agencies Only 4 Final CARS-Delay_SystemDesign_18m_du.docx Confidential. Limited Circulation Document. Listed Agencies Only 1. Concept of Operations This document specifies the design of a new traffic analysis software module called CARS-Delay. The module—which will use Google Directions to help assess the traffic impacts of state DOT and Waze roadway “icon” events, plus potentially (later) CARS-App user reports, where available— focuses on 511 traffic-event impact assessment. Instead of just reporting what is happening on the roads, CARS-Delay aims to allow agencies and the public to see the quantified impacts of traffic events, or (in San Diego only) to monitor corridor travel times. A group of state and local government agencies uses CARS (Condition Acquisition and Reporting System) as a reporting tool for highway-related event and condition reports. Examples of CARS reports include accidents/incidents, roadwork, traffic delays, winter driving, special events, evacuations, and natural disasters. The CARS software maintains a current events database, and allows the exchange of event reports with other centers and subsystems. Add-on modules facilitate the sharing of traffic/travel reports with the public via 511 telephone, highway advisory radio, the Web, Apps, and email/pager/text message notifications. An operational need has been expressed for a new CARS module that could automatically bring in delay information to CARS event databases, making 511 reports more meaningful to the public and agencies. The group’s Google Maps license and its “Directions API” allows travel times and delays to be returned in response to specific queries. The Directions API continues to be enhanced and its coverage extended as new innovations and data sources become available. CARS Summit meetings successively concurred that the Google Maps license may have potential as a cost-effective data source for integrating traffic delay data into the CARS/511 systems, starting modestly and progressively covering more highways and event types on an experimental basis. The Google Directions API service calculates current travel time and directions between specified locations using an HTTP request. Users can search for directions via several modes of transportation—the current modes being driving, transit, cycling or walking. The CARS-Delay module will use Google’s driving mode. Direction queries specify an origin, a destination and any intermediate waypoints either as text strings (e.g. "Ames, IA") or as latitude/longitude coordinates— the method to be used in CARS-Delay. Requests without “hard” intermediate waypoints return Google delay information, at times and on routes where enough vehicles are being tracked. The data will be used to estimate current delays at CARS event locations such as roadwork and crashes. Idaho’s BlueTOAD traffic speeds deployment—which calculates travel times for fixed roadway sections by detecting and timing passing Bluetooth IDs—originally gave rise to the original concept for CARS-Delay. While testing the delays at a road work site in Eagle, ID, it became clear that similar or perhaps even better results could be obtained through the systematic application of Google’s driving directions API. This experimental, multi-state pilot project is a direct result of that insight. In this project, each CARS-Delay query will include only one origin and one destination, with no “hard” intermediate waypoints—as required for quantified delay data to be returned by Google. At two-way traffic