By the end of Lesson 6, you should be able to:
Last week, we explored the purpose and components of an LRS. This week, you’ll have an opportunity to solidify your understanding by completing some hands-on exercises to create routes, calibrating linear measures along a route, and using dynamic segmentation to convert event tables into event features. You’ll also see how GIS software can be used to reduce the burden associated with the creation and management of an LRS and event data.
In the past few years, ESRI has been promoting their Roads and Highways product which is designed to provide a fuller featured set of tools for transportation organizations to manage their LRS and roadway event data. A 57-minute introduction to this tool [1] was provided at the 2013 ESRI users’ conference.
Transportation organizations capture and maintain a large number of linearly referenced roadway events including:
Displaying more than a few of these on a single map can begin to clutter the map and make it difficult for the user to understand.
One tool which transportation organizations have used for many years to visualize road attribute information is a Straight Line Diagram (SLD). In an SLD, a roadway section of interest is presented as a straight line along with various roadway attributes or events. Often, these roadway attributes are maintained by separate groups within the transportation organization, and sometimes they are linearly referenced using different LRMs. An SLD brings many attributes together with a uniform referencing method to facilitate visualization of the data and the potential identification of relationships between different data elements.
The specific layout of SLDs varies from one organization to another. One common layout for an SLD includes three components: a map component, a schematic component, and an attribute component. The map component often appears at the top of the SLD and presents the alignment of the route of interest. The schematic component, sometimes referred to as a stick diagram, presents the route as a straight line and can incorporate roadway features such as intersections, bridges, ramp entrances, and exits and legal boundaries. The attribute component includes roadway event data presented along the same horizontal axis. Linear events such as speed limit are displayed as a series of horizontal bars with the extent of each bar corresponding to the region over which the attribute has a constant value. Point events are displayed as point symbols positioned according to their location along the route.
Historically, SLDs were manually created and assembled into books for reference across the organization. Given the effort required to generate SLDs in this manner, the books often reflected data which was somewhat dated. Today, most SLDs are created dynamically from current event data using sophisticated GIS software applications.
As an example, the Massachusetts Department of Transportation uses a web-based tool called Massachusetts Route Log [2] to generate Straight Line Diagrams (SLDs). Here is an example SLD generated from this application for a portion of State Route 9.
Vermont’s Agency of Transportation (VTrans) has a similar SLD tool called VTrans Routelogs [3].
This week, you’ll take some time to get to know the American Association of State Highway and Transportation Officials (AASHTO). AASHTO is an association comprised of representatives from the state transportation agencies in all 50 states, the District of Columbia, and Puerto Rico. AASHTO seeks to promote transportation excellence and integration across the U.S. and to foster effective communication and cooperation between the state DOTs and the federal government. Founded over a century ago, it was originally named the American Association of State Highway Officials (AASHO). As with state DOTs, its focus has broadened over the years, and in 1973, it was renamed the American Association of State Highway and Transportation Officials (AASHTO) to reflect the fact that its scope of activities spans all modes of transportation.
AASHTO administers a variety of technical programs. A few of their more significant areas of activity are briefly discussed below.
AASHTO establishes technical standards and guidelines which are generally adhered to by the state DOTs in addition to many organizations outside the U.S. It has published many highly respected and widely used reference documents spanning a variety of transportation disciplines including the following:
AASHTO manages a program aimed at providing exceptional enterprise level software to transportation agencies. These products incorporate the experience and expertise of its member organizations and have been developed using pooled funds from state DOTs and the FHWA. The suite of software developed in this program is collectively known as AASHTOWare and its products span 5 core business areas:
An overview of the AASHTOWare program is provided in this 7-minute video [4]. AASHTO also publishes a catalog of AASHTOWare products [5]. Many of the AASHTOWare software products incorporate varying levels of spatial technology. For example, the bridge products use the Google Maps API for spatial analysis and visualization.
AASHTO is very active in the area of transportation research. A substantial portion of the research AASHTO promotes is carried out by the National Cooperative Highway Research Program (NCHRP).
The AASHTO Materials Reference Laboratory [6] (AMRL) develops protocols for testing construction materials and accredits laboratories who test these materials. Many state DOTs require laboratories to be AMRL accredited before they will do business with them.
AASHTO also operates the following three centers of excellence, each of which is designed to provide information and expertise in a specific area of transportation:
There are no one-on-ones scheduled for this week.
Next week, we will have a webinar with Doug Tomlinson, Chief of Traffic Operations at the Pennsylvania Department of Transportation. Doug's career has focused on various aspects of traffic engineering including work zone traffic control, traffic signals, traffic calming, incident management, ITS, and Traffic Operations. He is currently a Chief of Traffic Operations for PennDOT's Bureau of Maintenance and Operations with a focus on Planning and Operations.
Doug has worked for PennDOT since 1994. He was named ITS PA person of the year by the Pennsylvania chapter in 2013. Doug was a graduate of PennDOT's first Executive Development Academy, as well as a 2008 Graduate of the Operations Academy. Doug graduated Magna Cum Laude from the University of Pittsburgh at Johnstown in 1993 with a B.S. in Civil Engineering Technology.
Intelligent Transportation Systems (ITS) is an exciting subfield of transportation which encompasses a broad array of technologies. The unifying goals of ITS technologies and systems are to help us use our transportation network more effectively and to allow us to make more informed decisions. One of the most active areas within ITS is in the area of Connected Vehicles and Autonomous Vehicles (CV/AV). Check out this TED talk [7] (4:06) from 2011 on Google's driverless car:
An area of ITS which has become very popular in recent years is traveler information systems. These systems disseminate real-time information to travelers in order to allow them to make more informed choices. These systems commonly contain the following types of information:
Traveler information can be disseminated by a number of methods including via Highway Advisory Radio stations (HAR), Variable Message Signs (DMS) and 511 websites, mobile applications, and IVR systems. On July 21, 2000, the Federal Communications Commission designated a single 3 digit number (511) which could be used anywhere in the nation to obtain traveler information. Implementation of the services themselves was left to states and local agencies.
The Federal Highways Administration (FHWA) hosts a 511 Travel Information Telephone Services [8] website which shows the locations in the U.S. which provide 511 telephone services. As you can see from this site, most states in the U.S. operate a 511 information service. If you click on any location with 511 telephone services, you'll be given more information about the 511 services of that state/location. You'll notice that there is a “backdoor” number you can use to call 511 in a state even if you are not in that state. The information provided also gives the link to the corresponding 511 website if there is one.
In this lesson, we explored how GIS tools can be used to help maintain an LRS and event data. We also examined dynamic segmentation, a process used to convert event data into event features, and some very useful diagrams known as Straight Line Diagrams (SLDs).
Our transportation organization of the week was AASHTO. We reviewed some of the important roles AASHTO plays in establishing policy, producing important guidance documents, conducting and promoting research, and in creating exceptional software products for a number of functional areas in transportation.
In our weekly webinar, we had the chance to interact with Bill Schuman, Sr. Vice President of Project Delivery for Transcend Spatial Solutions, and benefit from his expertise and many years of experience in the area of LRS. We also had the opportunity to interact with Derald Dudley, a geographer and computer scientist with the USDOT's Bureau of Transportation Statistics (BTS).
In preparation for next week’s webinar, we also spent some time learning about intelligent transportation systems and, in particular, traveler information systems.
If there is anything in the Lesson 6 materials about which you would like to ask a question or provide a comment, submit a posting to the Lesson 6 Questions and Comments discussion. Also, review others’ postings to this discussion and respond if you have something to offer or if you are able to help.
Links
[1] http://www.esri.com/videos/watch?videoid=2679&channelid=LegacyVideo&isLegacy=true&title=esri-roads-and-highways---an-introduction
[2] http://services.massdot.state.ma.us/mrla/RouteSelection.htm
[3] http://vtransmaps.vermont.gov/routelogs/map.htm
[4] http://www.youtube.com/watch?v=iF7htviiQNI&t=33s
[5] https://www.aashtoware.org/wp-content/uploads/2018/03/E-FY2018_Catalog-Final.pdf
[6] http://www.amrl.net/
[7] https://www.ted.com/talks/sebastian_thrun_google_s_driverless_car
[8] http://www.ops.fhwa.dot.gov/511/