By Steve Slusarenko
Mapping is one of the earliest technologies known to man. The oldest known permanent maps are dated from 14,000 BCE and perhaps earlier. Maps are a powerful communication tool that allows the map user to orient themselves to features that are depicted on the map. Is that all there is to a map? Not really… The content of the map is so much more than a visual depiction of something’s location. It also provides information about the “something”. Early maps used symbols to depict rivers, lakes, pathways, and mountains. Maps today are interactive and do more than display the nature and location of certain features. They allow users to create new features, correct the location of existing features, or provide updates on the status and condition of features, and identify specific attributes of that feature such as material type, size, owner, manufacturer, etc. For most consumer users of maps, we would see information such as street names, business locations and even things like opening and closing hours, contact information and even traffic conditions on various routes from our current location to that business.
The intent of this white paper is to give the reader an understanding of the current state and latest trends in mapping technology. Also described are some of the issues that are experienced by civic bodies and their constituents and how enhanced mapping resolves many of these issues by using recent advances in technology to enrich map data and share it digitally.
It is fair to say that all Municipalities are concerned about what lies beneath their streets and boulevards. Many times the installation of new infrastructure is delayed due to the discovery of old infrastructure that was unknown or where the location shown was inaccurate and as a result the infrastructure is damaged. As the safety of both excavation personnel and the general public are paramount, State and Provincial One Call Centers have spent years developing and improving systems for mitigating incidents. One such system is 811’s “Call before You Dig” program. The One Call process has really helped prevent many incidents, however it relies heavily on having complete and accurate data. In spite of the systems in place, in the US on average, there is an infrastructure damage event every minute of every day. The lack of timely, accurate information is a major problem that is concerning for all of us as it causes utility strikes that put workers, residents and the environment at risk.
How the problem came to be
Municipalities have been installing and maintaining infrastructure assets for thousands of years. Early works were pretty simple constructs and there were likely no issues relating to crowded utility corridors or hazardous contents as the systems were generally related to provision of water, storm sewer, or sanitary sewer most of which was not buried at all.
As populations grew over the centuries, the picture changed and with urban densification came the practice of placing infrastructure underground to free up valuable space on the surface. Documenting the installation was done using simple maps that depicted locations of infrastructure relative to an existing feature, such as the wall of a building or other feature that (at the time) was thought to be fairly permanent. Fast forward a few centuries and you can appreciate that these old maps that were adequate enough for the day, are now unusable as the references are gone. Even as late as thirty years ago, maps were based on relative positioning and as the survey methods and instrumentation improved, the fundamental inaccuracies started to come to light. To help resolve these accuracy issues, geodetic survey datums were created so that the reference to these relative positions could be corrected.
Many businesses and institutions realised the benefit of electronic records and translated the information that they had into an electronic format. In the 1960’s and 70’s Computer-Aided Design (CAD) and later in the 1980’s Geospatial Information Systems (GIS) computer applications made the creation and sharing of maps much easier. Although these records were now digital, unfortunately, there was no way at the time to improve the reliability of the maps, so the issue of inaccuracy due to relative positioning remained. In spite of these systems, there still remained the issue of infrastructure that did not appear in the GIS or CAD system of record. Often, the maps depicting their nature and location were either lost or just not entered into the system of record at all.
Adressing the Problem
The good news is that with the technology that we have available today, we can virtually eliminate infrastructure damage events caused by human activities. With the right approach, we can ensure that every time we perform work in the field, we capture the precise location of new assets that are installed and the precise location of existing assets. When we do capture these locations, we use the Global Navigation Satellite System (GNSS) more commonly known as a Global Positioning System (GPS) to record the absolute position of created map features. While this system is relatively new, we all use it every day when we search for a restaurant near us and get driving directions to it. It is ubiquitous, and as the positions created do not relate to temporary features. The maps created using GNSS remain accurate for all intents and purposes and even tectonic plate movements can be factored in if millimeter accuracies are required.
Just a few years ago, a single piece of the equipment required to achieve these accuracies would cost approximately $50,000. To process the location data and plot it on a map would require hours of effort and involve several people. Today, devices can attain the same accuracy may be purchased for one-tenth of the cost, and the data is captured and plotted on the map in real time by one person.
How Municipalities are improving their maps
Old-fashioned paper maps were often already out-of-date by the time they were issued. The process of data collection, map creation, publication, and distribution was very expensive and the entire process was time consuming and labour intensive.
Today, maps are interactive and constantly being updated via web services. For all of us, this means that we no longer have to carry books of paper maps with us. We now have access to digital maps that are much more information rich than their paper predecessors. The information on the map is much more current and the time and cost to update is much less. We can now select a map feature and immediately view information that will provide us with much needed clarity and bring timeliness to the decision-making process.
Interactive digital maps present many benefits to municipalities. In just the one case where the City wants to register newly installed infrastructure by a third-party contractor, the receipt of this information could take weeks to receive and record using the old paper-based system. With digital records, this can now be done electronically. Due to their digital nature, real-time review and registration of these records is now possible. The availability and accuracy of this information to Engineering when doing design work will help ensure that designs do not require substantial rework when field work identifies major discrepancies during Subsurface Utility Engineering (SUE) investigations. Having good information translates to more efficient operations, especially when one objective of performing work is to do it with minimum disruption to commuters and residents. Many projects now are moving to a progressive design-build model where the ability to quickly react to field conditions allows for reduced costs and schedule impacts.
To take advantage of the technology not much investment is required and the return on investment (ROI) is almost immediate. Typically, Municipalities already have an investment in survey equipment, and in many cases, this equipment can be utilized with mobile mapping applications that are created specifically for precision mapping and collecting data in the field. An additional benefit is that the data collection mobile apps provide secure access, are simple to use, and can be configured to support any level of accuracy that is required.
In some jurisdictions, such as the City of Calgary, bylaws require contractors delivering public works projects or working on municipal lands, to submit electronic files. Programs like Calgary’s Joint Utility Mapping Project (JUMP) are substantially improving the information and reducing the number of utility damage events (Calgary saw a 36-fold decrease). One of the major outcomes of this legislation is that not only the City, but also the Utility companies, are enjoying the benefit of better records and their employees, contractors, and the public are safer for it.
Let’s use the example of the One Call Damage Prevention process, also known as the “Call before you dig” or “Click before you dig” process. When an excavation request (locate ticket) is submitted by the party performing an excavation to the One Call Center, the One Call Center Agent creates a locate notification (also known as a “one call ticket”) that is sent out to any Utility Companies that have buried assets within the vicinity of the excavation site identified by the excavator. The utility owners then determine (based on the location of the excavation site identified, its proximity to their assets, and their level of confidence in the accuracy of the location shown on their records) whether to give a clearance to dig to the excavator, or send out a locate technician to determine and physically mark the precise location of their assets. The locate technician will then make the excavator aware of the location of the infrastructure so that it is not damaged. Often the locate technician is sent out only to find that the actual location of the buried facilities is not where it is shown in the system of record. Historically, due to the difficulty of capturing and sending the actual location to the utility owner, discrepancies were not noted and therefore the records were not updated. If we capture the exact location of all buried assets in a digital format, we can ensure that the information needed by the Utility owners is made available to them so that they can confirm the accuracy of their records, or correct them to meet requirements.
 Geoff Zeiss, https://geospatial.blogs.com/geospatial/2019/05/city-regulation-reduces-underground-utility-damage.htmlThe good news here for the member utilities is that locates being performed can be enhanced by using GNSS receiver to record the precise location of each data point collected and the data can sent to the utility owner. The data captured by the locate technician can be sent to the utility company to either confirm the asset’s location, or conversely if a discrepancy is found, update the record for that asset. In this way, the utility company paying for the locate technician receives a benefit in the form of improved records. This one time capture of the data during an existing truck roll may obviate the need for future locates as the Utility Company may be able to reduce the buffer zone that they place around their assets. These buffer zones can be in the order of 100 feet or more. Buffer zones are used by the One Call Center to determine if Utility Owners with assets nearby need to be notified of an excavation. The Owner may also review the proximity of their assets and determine if they will need to dispatch a technician to the excavation site to mark-out the location of their assets. If the Owner could update their records with accurate locations, this buffer could be reduced, eliminating a good portion of what the industry calls “over-notifications”.
In addition, this same technology can not only prevent the incidence of damage events and improve safety, but can also provide direct tangible benefits to Municipalities. Virtually all activities that are performed by municipal workers in the field have a geospatial aspect to them.
Let’s have a look at some Departments and some potential use cases for collecting data and creating precision maps in the field.
- Identifying road repair locations,
- Registering and managing pavement cuts performed by third parties
- Managing parking meters and signage
- Managing street furniture, bus stops and shelters
- As-builting new sewer/storm/water installations
- Tracking sewer line cross bore video programs
- Mapping subsurface assets such as street light electrical components
- Register the precise locations of critical shut-off valves and storm drains
- Managing real estate inventory
Parks and Recreation Departments
- Inventorying and managing trees and horticultural assets,
- Reporting/mapping/tracking invasive species
- Mapping and recording sensitive habitat areas
- Mapping and reporting condition of park benches and playground equipment
- Mapping subsurface assets such as sprinkler lines
Cost and other considerations
When looking at putting together a precision mapping solution, the first thing to consider is what practice areas or departments have mapping requirements. This will give you an idea of how many users you already have, and what resources they already have available to them. Your Survey Department in example may already have equipment that can be leveraged to provide a good portion of the equipment that they need. Others may have mobile devices that can be employed as part of the solution.
You will need to match the devices needed to produce the desired accuracy for each community of users. There are mapping standards that many cities are following to ensure the accuracy of their records. In the United States, the American Society of Engineers has publish the ASCE 38-02 Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data. In Canada, the Canadian Standards Association has published CSA S250-11: Mapping of Underground Utility Infrastructure. Both of these standards relate best practice in the collection of data to reduce risk and ensure confidence in the accuracy and reliability of the data. Both standards provide similar specifications for each Quality/Accuracy level.
This will dictate what particular configurations you will need to assemble using existing equipment, and what you will need to purchase.
Finally, you will need to decide how best to provide access to field users to data in the system of record (usually a GIS or CAD system) so that existing data can be sent to a mobile device and displayed in the field. The inverse is also true, you will want to be able to submit data collected in the field to the GIS/CAD Department so that they can obtain updates from the field users. To do this you will need an enterprise solution designed specifically for this task that will also act as a GIS system on its own for organizations that do not currently have a GIS. ProStar’s Transparent Earth is one such system.
Finally, you will need to look at the costs of any hardware components and data collection software that you will need to procure and determine budgets and priorities.
For many users with existing mobile devices that do not need sub-meter accuracy, all they will need to do is download the mapping and data collection mobile application, register, and log in. Most cell phones on the market today have native GPS capabilities that produce positions to about 2 meter accuracies.
If the survey crews already have precision GPS receivers and tablets, they too may only have to download the mobile data, register, log in, and connect the tablet via Bluetooth with the GPS receiver so that the app can record the geospatial positions from the GPS receiver rather than from the native GPS in the tablet.
If new GPS receivers are needed, there is good news on that front in that there are now several low cost/high accuracy receivers on the market that are tremendous value and can provide the desired precision.
- For mapping and reporting surface assets – native tablet GPS accuracy of 2 meters should suffice.
- For buried infrastructure assets a GNSS unit capable of 25 cm (sub-foot) accuracies is appropriate.
- For registering “as-built” or “as-found” assets to sub-centimeter accuracy an RTK unit is needed.
- For intermittent use, there are solutions in the market that use a low cost antenna and services that can be obtained via a monthly or even hourly (on-demand) subscriptions.
One of the greatest fears that anyone working near buried utilities has is that of having an incident on the job where someone is hurt, the environment polluted, or services disrupted. In spite of best intentions, these accidents still occur and infrastructure gets damaged. Most often, the accident is due to an equipment operator making a dig decision without having the information that would provide to them a full understanding of the situation. Often the information is available, but not available in a system that is available to the operator, or the information is incorrect and this leads to a bad decision.
In order to attempt to eliminate utility strikes the “Call before you dig” and “Click before you dig” processes have helped make work being performed on public lands much safer. While this has provided a reduction in damage events and has potentially saved lives and prevented property damage and pollution, these damages still occur. We need to do more…
Given that populations keep growing and that existing infrastructure is aging or needs to be enlarged, there are more and more demands for space in already congested corridors. Civic bodies are now mandating the use of precision data collection tools to capture and document what is buried in their utility corridors now, exactly where it is, what condition it is in, and how it will be managed.
To address this lack of accurate quality information there have been major advances in mobile mapping and data collection applications and cloud offerings that provide the backbone of the solution needed to integrate all of the technologies that are needed to deliver the desired results.
As in the case of the City of Calgary, mandating the adoption of an accurate data collection and precise mapping process has yielded benefits to all parties involved. The subsequent reduction in negative events should be the experience of every municipality.
Let’s embrace the technology, move the industry forward, and — above all — stay safe…
Interested? Here’s Some Links to ProStar Resources
Transparent Earth: https://support.prostarcorp.com/index.php?title=Transparent_Earth
BlueStar GPS: http://www.bluestargps.com/
How to Videos: https://support.prostarcorp.com/index.php?title=Help_Videos
Configurations to obtain desired results:
Transparent Earth Enterprise Solution (includes PointMan mobile app)
2 meter accuracy – Mobile device only (with native GPS)
Sub-Meter accuracy – Mobile device with Bluetooth to GPS Receiver
3 Decimeter accuracy – Mobile device with Bluetooth to GNSS Receiver
Centimeter accuracy – Mobile device with Bluetooth to RTK Receiver + VRS