Validation of Electronic Truck Delivery Ticketing of HMA Material

Generation of Digital Tickets to track time and placement of HMA material from production through lay down

Prepared by: Joseph Korzilius, Greg Symanietz, Michael Malsczycki, and Renae Kuehl, SRF Consulting Group

Summary Statement: This study pilots the use of electronic delivery tickets (E-Ticket) for reporting the delivery of HMA material. E-Tickets provide an electronic scale/delivery ticket with all the same information as a typical paper scale ticket and provides broader and more immediate availability. E-Tickets identify the tonnage and type of HMA material produced, when and how much HMA is deposited into the delivery truck, the location of the delivery truck during transport, anticipated arrival time, and documents time stamps for when the delivery truck leaves the plant, arrives at the project site and arrives at the paver location, then also records the location where mix is deposited into the paver or in a windrow.

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Background3Objective of this Research4Goals of this Research4Contract Specifications4Hardware5Software Reporting6Pilot Projects7Observations8Conclusions11Recommendations13

Background

The implementation of electronic delivery tickets (E-Ticket) for reporting the delivery of HMA material is of great interest to agencies and contractors. Paper batch tickets that meet MnODT standard specifications identify the tonnage of material delivered for each load of HMA, a total for the day, and required information that includes the mix type designation, a mix design report identifier, identifiers for the project and delivery vehicle, the date and batch time, and other information. The E-Ticket is an electronic form of the required paper ticket with the same information. Paper tickets are collected by an agency inspector as the HMA material is dumped into the paver certifies for the agency that the material was delivered and is retained for payment. The paper ticket system requires an agency person to be at the paver to collect each ticket. An electronic ticket allows an agency inspector to move about and observe the entire paving operation and review all delivery tickets before material arrives to the project site. E-tickets are retained in a database where they will not be lost.

E-tickets assist inspection efforts by allowing an agency inspector to focus on the overall work as it is performed rather than having to collect paper delivery tickets as HMA material is delivered and prior to being deposited in the paver or windrow.

In addition to supporting agency inspection efforts the E-Ticket system provides a significant enhancement to inspections with the inclusion of GPS tracking of the delivery vehicles from the point of production to the point of placement. The verification of HMA material placement, location and time is enhanced by having the ability to capture time stamps at defined points throughout the delivery process or route. Virtual geofences are established around the plant at the point of production, the project area, and in close proximity to the paver. A time and location stamp is generated and recorded as delivery vehicles with the tracking system on board emit location information when located within an area delimited by a virtual geofence. The GPS tracking and time stamps are a significant enhancement to the paper ticket system where an inspector must note, by hand, delivery time and location on a scale ticket. The E-ticket is an efficient method of recording this information with the potential for increased accuracy.

Reporting and GPS tracking provides a significant benefit to overall project quality. For the contractor, monitoring efficient delivery of material to the project is important to keep the paver moving and eliminate stops. Efficient delivery to the project is expected to provide more uniformity in construction. A consistent flow of material to the paver is critical for smooth, consistent paving which is important to both the contractor and agency.

This pilot project observed the E-Ticket system presently available from Caterpillar identified as “eRoutes”. The eRoutes system provides electronic scale tickets and reports the location of HMA loads being delivered and anticipated arrival time to the project as every load is tracked by GPS locating. eRoutes is a web-based password protected application for smartphones and computers accessible to people that have been granted access.

Objective of this Research

The objective of this pilot research is to observe the E-Ticket system presently available from Caterpillar identified as “eRoutes” and evaluate the use of electronic tickets for reporting, documenting, and maintaining delivery tickets and the effectiveness of using a Global Navigation Satellite System (GNSS) to monitor delivery of HMA mix from the point of production to point of placement.

Goals of this Research

For this pilot project the following goals were identified:

To verify the availability of the E-Ticket prior to HMA material delivery. This step includes evaluating the ability to access E-Tickets and being able to read on a mobile device, (smartphone, laptop, tablet).

To validate the correctness of E-Ticket information relative to the information provided with the typical paper delivery ticket and the required specification.

To observe the GPS tracking system reporting the delivery of HMA including delivery vehicle locations and transport times.

To confirm time and location stamps at the plant (point of production), upon arrival to the project, and when unloading at the paver (point of placement).

A smartphone and laptop computer were the mobile devices used to verify E-Ticket availability. For this pilot project, paper scale tickets remained the required method of material tracking for contractor payment. To validate the correctness of the E-tickets, comparisons were performed randomly throughout the paving process and on all E-Tickets once all paper tickets were available. Throughout the delivery process the web application was monitored and observations were made relative to the software’s ability to identify the location of delivery vehicles and forecast arrival to the project. As delivery vehicles entered the project site and again as they approached the paver for unloading observations were made as to the accuracy of time and location stamp reporting.

Contract Specifications

The full specification provided to the contractor (see Appendix) defines the requirements for the E-Ticket pilot research.

For bituminous paving “MnDOT Standard Specifications for Construction” require a contractor to provide automated weigh scale and computer-generated paper weigh tickets that report the following information to the inspector on the project:

1. Date and Time of Loading

2. Project Number

3. Contract Item Number

4. Mix Designation including binder grade

5. Mixture design report number

6. Truck or Tractor Trailer Identification

7. Truck Tare

8. Net Mass

The E-Ticket pilot specification additionally requires the contractor (producer) to include the sample ID for test samples taken from the truck box at the plant site and make E-Tickets available through cloud storage and/or cloud computing with location information updated every 5 minutes, or less; or when there is limited cellular coverage at least once per day. E-Tickets are to be compiled and exportable as a dbase ASCII or text format. A PDF format is optional.

The E-Ticket pilot specification requires the use of Global Navigation Satellite System (GNSS) and Geofence’s. A GNSS is utilized to continuously track delivery truck locations. A GNSS is a generic name for a group of artificial satellites that send position and timing data from their orbits. The GPS, Global Positioning System, is one of the many different sets of GNSS satellite groups that can provide such data. Geofence’s are virtual geographic boundaries defined by GNSS technology. Time stamps are dynamically generated and associated with GPS location information when a signal device emits a ping when located within a virtually defined perimeter area. Geofences were established around the production plant, the project site, and the paver for this pilot project. Time and location stamps are dynamically generated when a transmitting device, carried on material delivery trucks, emitted a signal and within a geofenced area.

For truck cycle tracking the specifications require real time reporting of E-Ticket information, delivery truck identification, number of delivery trucks in transit, as well as the tons of HMA mix scaled at the plant, in transit and paved.

Hardware

MnDOT standard specifications for bituminous paving require producers to generate automated electronic computer weigh scale tickets. These standards require the computer-generated paper weigh tickets, which the driver must print after loading and present to the roadway inspector at the time of delivery, provide the date and time of loading. At the point of delivery the agency inspector collects the ticket and can record the time and location for delivery, this is not automatic.

To track truck location, route, and document specific events time and location stamps are generated and recorded when triggered by a delivery vehicle entering into and/or exiting from an established virtual geofenced area. GNSS transmitters can be mounted on any and all pieces of equipment and emit a location tracking ping at a defined interval. A one-minute interval between pings was selected for these pilot projects. If a vehicle enters and then leaves a geofenced area in a period of time between the ping signal interval a time and location stamp is not recorded. The time and location data is captured at the plant, jobsite, and paver and stored in a database.

PaveTag, a software system and mobile application, create and magage the geofenced areas and position data emitted from a GNSS transmitters to the database (eRoutes). PaveTag access points placed at the plant and paver locations establish mobile or static virtual geofence areas and use a cellular modem as the means of transmitting data to eRoutes. Access points have an adjustable range setting that can be customized so that recorded events can be set with sensitivity to distance as well as duration relative to the paving contractor’s operations and job site. Data is processed and made available through the Caterpillar eRoutes Web Portal.

Software ReportingE-Ticket Digital Load and Scale Data

Figure 1 – View of Cat_Test on a Smartphone – Delivery Details

For reporting, Caterpillar’s eRoutes database portal provides data access through two software applications, “Cat_Test” or “PaveTag”. Both are available on a computer, tablet, and/or smartphone. Ticket load information and time stamp data is available through both applications.

Cat_Test

The Cat_Test application appears to be more suited to viewing with a smartphone, providing delivery information, that can easily be viewed on a smaller screen (Figure 1).The application reports truck status data including time stamps when HMA is loaded into a delivery vehicle, actual arrival times to the jobsite, and the time material is deposited into the paver or on the roadway.

PaveTag

PaveTag is be better suited to viewing on a larger computer or tablet screen and provides options for data analysis and optimization of the material delivery cycle and exporting data and information. Ticket load information and time stamp data is in a format that is exportable and printer friendly.

Figure 2 – Example report from the PaveTag Application

Material Delivery Tracking and DataCat_Test

Figure 3 – View of Cat_Test on a Smartphone – Materials Delivery and Transit Cycle

This reporting allows an agency inspector to monitor in real time material delivery and arrival time without guessing or relying on estimations from field personnel. The Cat_Test application reports when delivery trucks depart from the plant, the number of trucks in route, and the estimated arrival to a jobsite for the next delivery vehicle. Daily HMA material produced, in transit, and placed are continuously reported in real time.

Delivery truck ticket material information, location, and anticipated cycle times are registered by Cat_Test through cellular signals, for this pilot project transmitted on a 1 minute refresh rate. This feature is real time and available anytime and anywhere with approved access.

Pilot Projects

Figure 4 – Pilot Project 1 – City of Edan Valley

For this pilot research study, two HMA resurfacing (paving) projects were selected. The Cat_Test and PaveTag applications were accessed for information at both Pilot Project locations.

Pilot Project 1

The first project is located in central Minnesota in the City of Eden Valley along Minnesota Trunk Highway 22 from Fredericks Avenue (Southern limit) to Minnesota Trunk Highway 55 (Northern limit). The project is approximately 0.3 miles in length. This project is identified as Minnesota State Project (SP) 4710-27.

The Contractor was Knife River Corporation and HMA mix was produced from a portable plant owned by Knife River.

Figure 5 – Pilot Project 2 – City of New Richmond

Pilot Project 2

The second project is located on Minnesota Trunk Highway 13 between Minnesota Trunk Highway 30 in the City of New Richland (southern limit) to one mile south of Minnesota Trunk Highway 14 in the City of Waseca (northern limit). The project is approximately 11.6 miles in length. This project is identified as Minnesota State Project (SP) 8101-57.

The Contractor was Ulland Brothers Inc and HMA mix was produced from a portable plant owned by Ulland Brothers.

Observations

The following section documents observations made at the pilot locations.

General Observations:

1. Electronic tickets generated by the Caterpillar eRoutes system appeared to meet the specification requirements and provided the same information as computer generated paper scale tickets that typically accompany HMA loads. In a review of the paper scale tickets, compared to the digital scale ticket information, the ticket information matched.

Electronic tickets were available to inspectors on site prior to a delivery vehicle arriving to the site as work progressed.

2. During the pilot project a system interruption did occur and it appeared that eRoutes was not reporting total batched tonnage correctly after that point. Also, when delivered tonnage required four characters or more in length the total batched tonnage did not appear to be reported correctly. Both of these ticket reporting issues observed during our short time on the pilot projects were resolved and occurred due to a configuration issue with the plant device.

3. The Cat_Pave application provided anticipated HMA material delivery with good accuracy. This application allowed the user to see icons displaying the apparent location, based upon the GNSS signal and updating at the one minute intervals. The option to see vehicle location on a map at the time of each ping was available and was operating. The PaveTag application did not appear to provide the same visual tracking of truck paths/routes.

4. When paving two separate mixes simultaneously at different pavers on the same project the system appeared unable to report more than 1 HMA mix design correctly. This is believed to also be a configuration issue at the production plant.

5. Printing a paper scale ticket from eRoutes was not an option. The scale ticket data was available printed in a tabular format from the PaveTag application. A smartphone can take a screenshot of any ticket if necessary.

6. The eRoutes system did not post paver deposit times for all deliveries. The paving operation was moving very quickly and it is presumed that delivery vehicles were not within the geofenced area at the time the GNSS transmitter emitted a signal within the one minute interval.

7. The location of the delivery vehicle was not identified at the time HMA material was being deposited into the paver.

Pilot Project 1 Observations

Paving along Minnesota TH 22 commenced on June 27, 2018. This was the first of the two pilot projects and on-site support was provided by Caterpillar. The following observations were made as the paving work progressed:

1. Due to server connectivity at the start of the project the electronic ticketing did not register the first thirteen loads. In a review of the project files using the PaveTag application, the electronic load ticket data for the first 13 loads was manually entered into the Caterpillar database.

2. The pavers were not initially emitting a signal (pinging) and it was determined that the geofence area was not configured correctly. This was reconfigured and then began to transmit data correctly.

3. E-tickets compared well to companion printed tickets except for the total tonnage delivered at the plant, when checked at various times throughout the day. It was also found that the E-tickets were available concurrently in real time.

4. During paving, the running total of tons produced did not appear on the E-ticket. At the time of paving, the running total that was available in the PaveTag software appeared inaccurate as it did not include the first 13 loads. All other data reported on the E-ticket appeared to compare well to printed tickets when checked at various times throughout the day.

5. There were periods of time when the Cat_Pave application, used to track delivery truck status, did not appear to be updating within the 1-minute time frames. An example is when a delivered load that was shown as “in transit” on the application, had actually completed unloading at the paver and left the project prior to the application updating. This was observed as missing time stamps in the database as well.

6. While paving in echelon, in some instances the applications identified trucks depositing material to the adjacent paver. Caterpillar support staff identified that geofenced areas were circular for this project and pavers working in echelon likely have overlapping geofence boundaries. Truck route and location at the time the GNSS transmitter emits a signal can contribute to which paver a vehicle connects with when pavers are in close proximity.

7. At least one instance was identified where a delivery truck connected with multiple pavers for the same load while on site.

8. When using three pavers on a project and not paving in echelon (two paving entrances and a third paving shoulder area), trucks appeared to connect with the correct paver.  The pavers apparently were separated by enough distance and durations were such that while in transit delivery trucks did not connect with or register to the wrong paver. It was observed however that the trucks entered several time stamps due to unloading multiple times per delivery to a single paver for the small disjointed paving at various entrances.

9. When a paver on our pilot project was transferred to a different project later in the day, the plant, trucks, and the paver continued to collect data for loads of HMA delivered to that paver. This did not adversely impact our pilot project as this was extra data.

Pilot Project 2 Observations

Paving along Minnesota Trunk Highway 13 in the City of New Richland commenced on June 28, 2018. This was the second of the two pilot projects, the same system and on-site support was again provided by Caterpillar. The following observations were made as the paving work progressed:

1. E-tickets compared well to companion printed tickets at the plant when checked at various times throughout the day. It was also found that the E-tickets were available concurrently in real time.

2. Initially the Cat_Test application did not report the running total of tons. After about 20 minutes Cat_Test began reporting the running total correctly.

3. Trucks (loads) did not initially appear in the Cat_Test application until after the first truck arrived within the geofence of the paver.

4. After the first day’s paving and arrival of the first delivery truck to the paver, the first and subsequent loads were visible in the Cat_Test application as they are loaded at the plant.

5. It was observed at random times that tracking for a truck would fail to show up on the Cat_Test application. Even though there was a failure of the web-based application in its ability to communicate the Geo location at times, the PaveTag program kept tracking and recording data throughout the day. It appeared that the GPS unit was unable to emit a reliable or consistent signal. This may have been due to its position or location within the delivery truck. The drivers were instructed to place the tracking devices on the dash and it is unknown whether devices were correctly placed or remained in place during transit.

6. The PaveTag application did not initially come online for the first three hours of paving. PaveTag began reporting for about 45 minutes before dropping offline again. After another two hours PaveTag appeared to come back online.

Conclusions

There were four goals identified for this project. Conclusions for each goal are provided below.

1. Verify the availability of the E-Ticket prior to HMA material delivery. This step includes evaluating the ability to access E-Tickets and being able to read on a mobile device, (smartphone, laptop, tablet).

Collecting scale tickets, paper or electronic, serve as a certification of and are receipts for payment confirming the required HMA material and the quantity delivered to the project therefore are very important. For both projects E-Tickets were generated and accessible using a smartphone and inspectors were able to verify availability of the digital E-Ticket on a mobile device (smartphone, tablet, or laptop computer), prior to HMA material delivery. E-Tickets were not available when system interruptions occurred. In the pilot projects, E-Tickets appear to have been generated but interruptions in connectivity made the tickets temporarily inaccessible, not lost.

2. To validate the correctness of E-Ticket information relative to the information provided with the typical paper delivery ticket and the required specification.

Based upon observations at the two pilot projects other than the total tonnage delivered, eRoutes provided E-tickets that compared well to companion printed scale tickets. In general, E-Tickets were available to inspectors prior to HMA delivery, compared well to companion printed tickets, and accurately reported HMA and load information. There were instances where internet connection was interrupted and reporting of total delivered tonnage was impacted, but other portions of the E-tickets matched the computer-generated scale tickets.

3. To observe the GPS tracking system reporting the delivery of HMA including delivery vehicle locations and transport times.

The GPS tracking component of the Caterpillar eRoutes system did report vehicle location and allowed inspectors to monitor and anticipate material arrival times to the project with good accuracy

4. To confirm time and location stamps at the plant (point of production), upon arrival to the project, and when unloading at the paver (point of placement).

Time stamps for vehicle location, delivery trucks, were generated and maintained when the delivery vehicle emitted a ping and was within an area that had a virtual geofence established. A virtual geofenced area was established around the point of production (paving plant), the project site, and the paver (point of placement). For both pilot projects geofence configurations at the production plants were polygons drawn around the plant boundaries. Geofence configurations around the project and pavers were reported to be circular. It is anticipated that in the future geofence areas will be completely configurable for shape and distance. Configurable geofences will aid in reporting locations when paving in echelon or paving operations in close proximity. The location of the delivery vehicle was not recorded at the time HMA material is being deposited into the paver. The location of the HMA delivery point, although not directly recorded, is available by correlating the time stamp within the pavers geofenced area with a location and time stamp regularly generated and maintained for the paver at one minute intervals.

General Conclusions

· Based upon pilot project experiences, E-tickets can be expected to provide significant improvement to efficiency relative to collecting and managing paper scale tickets. Agency inspectors can more efficiently utilize their time inspecting the work rather than collecting tickets as material is delivered to a project, which often requires an additional person to perform the collections. E-tickets available electronically also assist with project documentation as these tickets do not get lost nor are they illegible or susceptible to adverse conditions such as rain.

· The E-Ticketing system observed through this pilot project is expected to be a significant advancement to the present system of generating and retaining paper scale tickets. The E-Ticketing system is intended to provide better accounting for paving projects by maintaining scale ticket information in a database and making the data available to agency inspection staff before material arrives at the site. In addition, the E-Ticketing system promotes better inspection of the overall construction being performed and efficiency by reducing focus on collecting paper receipts to confirm delivery and improved verification of HMA load placement.

· For the contractor, truck cycle time is important when monitoring efficiency, production rate and the transit of material between the asphalt plant and paver. Efficient HMA mix material delivery supports good quality construction by ensuring smooth mix delivery within the appropriate laydown temperature range, elimination of paver stops that can produce bumps, and assist with providing uniformity. The opportunity to improve construction quality is further supported with continuous delivery of material and supporting ongoing improvements being made to paving quality and encouraging uniformity associated with paver mounted thermal profiling, intelligent compaction, and measuring density by dielectric profile technologies.

· Uniformity and balanced production rates have been shown to improve the quality of construction and E-Ticketing supports and enhances the opportunity to improve quality. E-Ticketing technology automates data collection likely leading to better records control and has the potential to reduce wait times at the plant and paver. Contractor efficiency can also increase monetary compensation along with quality through optimized utilization of manpower and equipment as well as incentives.

Recommendations

Based on our observations, we have the following recommendations:

1. Provide E-Tickets as a printable pdf document and available in the paper ticket format. Provided the information is recorded and retained in a database, printing in any specific format is expected to be achievable.

2. Have automatic additional signals triggered when a GNSS transmitter crosses a geofence boundary or include the option to manually trigger a signal. An automatically triggered signal is most useful at the plant and again at the paver. A manual triggering system is a less desirable alternative that can be forgotten or neglected but would appear to be an improvement to the existing system of having a set interval. With automatic triggering the one-minute interval for emitting a signal could be significantly extended.

3. Jointly record time and location of the load when placed in the geofenced area and retain in the database. The system used for the pilot projects appears to record time for the delivery vehicle with the first signal emitted within a geofenced area near the paver. To obtain an estimated location for material placement, the recorded time is correlated to time and location data stored for the paver.

4. Having the ability to completely configure the shape and size of a geofence area about the plant or any piece of equipment. A configurable shape and size would likely provide improved reporting when paving with multiple pavers on a project as well as when paving in echelon.

Appendix

MnDOT Pilot Project Special Provisions

S-1 (2360) PLANT MIXED ASPHALT – E-TICKETING

NEW WRITE -UP 05/07/18 ◄DO NOT REMOVE THIS. IT NEEDS TO STAY IN FOR THE

CONTRACTORS.

SP2018-xx

MnDOT 2360 Plant Mixed Asphalt is modified with the following:

S-1.1 DESCRIPTION

This work consists of using a GNSS management system and ticket capture software for capturing

computer generated weight tickets into a digital format and tracking trucks during transit for recording of truck

exchanges.

A Definitions

A.1 COMPUTER GENERATED W EIGHT TICKET . The printed copy of the weight ticket

created by the load-out software.

A.2 E-TICKET. An electronic, digital version of the computer generated weight ticket that is

available through cloud storage and/or cloud computing.

A.3 GEOFENCE. A virtual geographic boundary, defined by GNSS technology that enables

software to indicate when a mobile device enters or leaves a particular area. It is dynamically generated using a

radius around a point location.

S-1.2 MATERIALS

Add the following to 2360.2.G.8:

G.8 Documentation

Provide an e-ticket containing the same information included o n the computer generated weight

ticket. Include the sample ID, for samples taken from the truck box at the plant site , on the e-ticket.

Ensure that the e-tickets are exportable as follows:

(1) All e-tickets are compiled and exportable as a dbase ASCII or text format (required) and

(2) Individual e-tickets are exportable in a *pdf format (optional).

Each truck driver will carry a co mputer generated weight ticket that is collected by the Engineer

on the jobsite and used to document the details of deliv ery. The Engineer will use the computer generated weight

ticket for the generation of density lots and the calculation of pay quantities.

Ensure e-tickets are available from cloud storage/computing in 5 minute, or less, intervals; or at

least once per day, when there is limited cellular coverage.

S-1.3 CONSTRUCTION REQUIRE MENTS

Add the following to 2360.3.B Equipment:

B.4 E-Ticketing

Use an e-ticketing system with a minimum of the following components:

(1) Software to digitally capture the computer generated weight ticket for creation of an e -ticket.

(2) Portable, or hardwired, GNSS systems to continuously track truck locations. Ensure that the GNSS system:

(2.1) Sends a location tracking ping in 1 minute, or less, intervals.

(2.2) Is powered independently, and/or through use of an adapter.

(2.3) Provides an indication of instances where there is an interruption in the availability of the sate llite

signals used to track truck locations.

(2.4) Is associated with corresponding truck identification and e-ticket.

(3) Hardware to establish a static, or mobile, geofence around the following locations:

(3.1) Plant – to capture e-ticket and identify associated truck load;

(3.2) Jobsite – to capture arrival of truck within the jobsite limits; and

(3.3) Paver – to identify location on pavement , within ± 100 ft, of where the load was delivered.

Ensure that the hardware allows for user defined creation of a geofence (i.e., both the geometric

shape of geofence and radial distance of the geofence from given location) and a user-defined duration within a

geofence to correctly indicate truck exchange s (e.g., delivered loads verses loads in transit).

(4) Cloud storage and /or cloud computing to allow for viewing and export of e -tickets.

(5) Real-time viewing, per paving day, of the following:

(5.1) Truck ID and associated e-ticket;

(5.2) Total number of e -tickets;

(5.3) Number of trucks in transit; and

(5.2) Tons scaled, in transit and paved.

(6) Continues to collect and store data when there is limited cellular connectivity.

Provide the Engineer with access to cloud storage and cloud computing prior to the start of paving

efforts until ninety (90) days after final acceptance of all work per MnDOT 1516.2.

Provide a user’s manual detailing the procedure for real-time viewing of the information listed in

item B.4.(5) and for export of e -tickets per the requirements of S-xx.2.G.8.

Instrument the appropriate components of the e-ticketing system on all:

(1) Plants providing material for project,

(2) Pavers completing the paving operation and

(3) Trucks delivering material to project.