Chapter 2. Mileage Recording Approaches and Their Attributes

The ability to accurately record miles is a critical component of any RUC system. This chapter explores the technologies and approaches deployed or tested as part of the STSFA Phase Ⅰ Program. The chapter also explores the various attributes of these mileage reporting options, including transparency, flexibility, ease of use, reliability, precision, accuracy, and repeatability.

Mileage Recording Approaches Explored By Phase Ⅰ Sites

The mileage recording/reporting approaches explored by the Phase Ⅰ pilot sites fall into the following broad categories:

• The vehicle’s odometer: These approaches use the vehicle’s odometer to measure miles driven to assess a fee. The different approaches explored by the grantees use different means of measuring the odometer reading, but the odometer itself is what is measuring the miles.
• The vehicle’s onboard diagnostic data:  Testing an onboard diagnostic standard II (OBD-II) dongle that measures the speed of the vehicle against time driven to determine miles driven. Diagnostics or telematics information is periodically transmitted over cellular communications to the account manager to report mileage and fee. Unlike an odometer-based approach, because the mileage is being calculated based upon the speed pulse available from the vehicle, the actual mileage recorded on the odometer, which is not included in vehicle diagnostics data, is not transmitted.
• Location-based technologies: These approaches use Global Positioning System (GPS) technology to measure the location of miles driven. These approaches add a layer of information and complexity to that of a basic mileage charge, but they also offer the ability to distinguish between different political jurisdictions and mileage driven on public versus private roads. Regarding interoperability, the ability to accurately measure in which jurisdictional boundaries mileage is driven is critical to reconciling mileage and fees between jurisdictions.
• Alternative (non-RUC) approaches: These approaches are not focused on deploying mileage recording approaches or technology, and do not have implications for the accuracy, precision, reliability, or repeatability of mileage recording and fee reconciliation.

Table 3 provides an overview of the site-specific mileage recording and reporting approaches.

Table 3. Mileage reporting/recording approaches and options tested or explored by Phase Ⅰ pilot sites.

Mileage Recording/ Reporting Approach	Mileage Recording/ Reporting Option	Description	Respective Phase Ⅰ Site
Odometer-based	Manual odometer reading	A visual reading of the vehicle’s odometer is made at the time of the annual vehicle inspections.	Hawaii, Washington
	Image-based odometer reading	Images of the odometer taken with a smartphone application that uploads the image to the account manager.	Washington
	Hybrid	Image-based odometer reading using smartphone application with location detection ability.	Washington
Onboard diagnostic-based	Onboard diagnostic standard II (OBD-II) port	OBD-II dongle measures the speed of the vehicle against time driven to determine miles driven.	Eastern Corridor Coalition
Location-based	Smartphone with location	Smartphone with Global Positioning System (GPS) enabled to track trip location for the driver. Phase Ⅰ grantees deployed or investigated several variations of this approach, including one site that was paired with image capture technology (see ‘Hybrid’ in the ‘Odometer’ approach above), and another that tested the technology with a Bluetooth beacon. Both approaches require the driver’s smartphone to be in the vehicle, powered on, and the application activated while driving.	Eastern Corridor Coalition, Oregon, Washington
	Plug-in device with location	OBD-II device to calculate mileage using vehicle diagnostics, and codes that data with location data provided by an on-device GPS device. The approach allows for the vehicle’s mileage to be calculated and for the location of that mileage to be measured.	Eastern Corridor Coalition
Alternative approaches	Fleet-based	Utilizes shared-vehicle fleet’s ability to track mileage and location is central to the ability to assess a mileage fee.	Minnesota
	Registration fee-based	This approach will not take miles driven into account but, rather, will focus on backfilling transportation funding gaps caused by shortages in the motor fuel tax with an additional graduated registration fee based on the vehicle’s fuel efficiency.	Missouri

Key Cross-Cutting Findings Regarding Mileage Reporting Options

• Meeting the goal of providing more mileage reporting options to the public: Several pilot sites’ approach to testing both technology- and non-technology-based options of mileage reporting is in line with the goal of providing more options to the public. Having multiple options to report mileage is likely to enhance ease of use and wider public acceptance. However, these attempts are in the early phases and benefit from a period of testing to determine their viability in a volunteer-based program before being implemented on a mandatory basis.
• Market forces: Significant changes in transportation usage patterns are likely in the future given the current growth in mobility on demand (MOD) and MaaS. New models for ridesharing, vehicle sharing, and vehicle ownership in partnership with automation are likely to create a greater demand for electric vehicles. Pilot sites have the opportunity to project future scenarios with a variety of travel and vehicle ownership patterns. However, this also poses the challenge of planning a system around a high degree of uncertainty.
• Emerging technologies: In addition to the options described above, some Phase Ⅰ sites are beginning to explore emerging technologies, such as those developed under the connected vehicles initiative; specifically, the vehicle-to-infrastructure communication technologies that can potentially allow vehicles to transmit large amounts of data, including information about miles driven. Wider adoption of electric vehicles is likely to coincide with wider availability of onboard telematics capable of connectivity with vehicles and infrastructure. While this could significantly enhance the methods and processes for data collection and aggregation, including mileage data, it can present both opportunities and challenges. Data access, ownership, and privacy considerations are likely to continue to be key issues in the application of emerging technologies to estimate RUC.
• Ability to pair new activities with existing activities currently needed for driving:  This ability can reduce the additional effort required by participants. Of the mileage reporting approaches considered, the registration-based fee, the fleet-usage fee, and the pay-at-the-pump fee offer a streamlined experience for the user, reduce the steps necessary to pay a fee, and reduce the complexity and actions required for the driver to manage the system. Approaches that rely on a smartphone require a high number of actions by the driver, and require the presence of the driver’s smartphone in the vehicle, powered on with the application running, to drive. The automated OBD-II approaches are less hands-on to operate, but similar to other mileage recording device (MRD) approaches, will have a separate bill to pay at the end of the billing cycle. Note, however, that the bill could be automatically deduced from an account, or even deducted from a pre-paid amount, thus reducing the actual effort needed by program participants.

Implementation Attribute: Accuracy, Precision, Reliability, and Repeatability

The proposed approaches for a revenue system based on miles driven should measure and report miles reliably and consistently. In other words, mileage reported should equal the actual mileage driven, and identical trips should produce the same reported mileage and fee. Note that several of these attributes were not fully or adequately explored with the activities from Phase Ⅰ of the STSFA funding, primarily because full testing and demonstration of technology was not part of this phase.

Phase Ⅰ grantees have explored a number of options for measuring mileage, including using a vehicle’s odometer, a vehicle’s onboard diagnostic-based telematics, location-based measurements, and non-RUC approaches. This report explores some of the relevant characteristics of these approaches and how accuracy, precision, reliability, and repeatability would be impacted. Note that pay-at-the-pump technology was not tested significantly enough to be able to evaluate its accuracy, precision, reliability, and repeatability.

Odometer. The accuracy or precision of the odometer-based mileage recording methods will be only as good as the reliability and functionality of the individual vehicle’s odometer. Vehicles without functioning odometers or with odometers that are inaccurate will not produce accurate information from which to record miles and assess fees. Of the odometer-based approaches, grantees have explored different ways to record and communicate the mileage reading to the account manager or the State:

• Manual odometer reading: Common errors may be in taking the odometer’s measurement, or a transcription error by the person viewing and reporting the odometer reading.
• Image-based odometer reading: When a driver sends an image of the odometer to the account manager, that image is matched with the account associated with the application used to take the picture. The image is “read” by an algorithm that codes the image into numeric data used to establish the vehicle’s mileage. There could be transcription errors with the process; however, those errors would be reconciled with the next reading.
• Odometer/smartphone hybrid approach with location-measuring features:  Smartphones are used to measure mileage driven out of State, but the base mileage is reported through image capture, which still relies on the odometer to measure the mileage driven.

The use of the odometer is likely to be accepted by the public, as this instrument has long been accepted by the public as a surrogate for vehicle condition. Capturing the odometer through manual, digital, or other mechanism is relatively straightforward, with only small margins for error introduced by the data collection mechanism. However, odometers are not a precision instrument, and they can be adversely impacted by a number of external factors (e.g., improper tire inflation and incorrectly sized tires). There is no national regulation regarding the accuracy/precision of odometers; rather, vehicle manufacturers adhere to a voluntary Society of Automotive Engineers standard. Federal Law 49 United States Code Chapter 327 (Public Law 103-272) does prohibit citizens from disconnecting, resetting, or altering a motor vehicle’s odometer with intent to change the number of miles, but does not provide a framework for odometer accuracy.

A key consideration for a national program would be enacting a national, regulatory standard. Systems based upon odometer readings cannot easily distinguish where those miles were driven (e.g., out-of-State versus in-State).

Onboard diagnostics-based technologies. The accuracy, precision, reliability, and repeatability of this approach is similar to that of an odometer-based approach, although the data are collected in a different manner. The mileage is calculated using speed combined with time, rather than the total vehicle-miles, as communicated through the odometer. However, if the dongle were removed or damaged, mileage would not be measured during that period, and a manual reading of the odometer may be necessary to re-establish actual miles driven with the account manager or State.

Location-based approaches. Several key components must be in place to ensure accuracy of location measurement, including visibility to the GPS satellite network, accurate maps that can define which roadways are public verses private, and an accurate delineation of jurisdictions.

Phase Ⅰ site efforts uncovered several considerations related to these approaches that may affect a reliable, repeatable, and accurate recording of mileage driven:

• Smartphone with location:  These approaches require the driver’s smartphone to be in the vehicle, powered on, and the application activated while driving. Two key approaches were tested in Phase Ⅰ:smartphone application with and without beacon.
  • For the approach that uses the beacon (as tested by Oregon), there were issues with the smartphone pairing with other available beacons, or the beacons pairing with other smartphones. In each case, the issues with the smartphone approach would have impacts on the system’s ability to accurately record miles reliably and precisely and to garner the exact same results from a repeat of exactly the same trip.
  • For the approach that did not involve a beacon (as tested by the Eastern Corridor Coalition), there were reported issues with smartphone reliability and the requirements needed for the device to record miles. Specifically, the device needed to be powered on, location and data services turned on, and the application activated prior to travel. The numerous steps needed for participants to use the approach led to a low mileage reporting rate from participants (57 to 62 percent for smartphone users, compared to 93 to 97 percent for an OBD-II device with location). Additionally, they found a delay between activating the application and when mileage would start recording mileage due to location services needing to verify and validate the location.
• Plug-in device with location:  From the Phase Ⅰ round of testing, this approach has reported few issues with accuracy, precision, reliability, and repeatability. Like the vehicle diagnostics MRD, the mileage is calculated using speed combined with time, rather than the total vehicle-miles as communicated through the odometer. With locational data, the mileage can also be determined based on GPS data, thus offering a second method to calculate mileage, which is important for electric vehicles that do not produce OBD-II data usable for mileage calculation. The downside of using OBD-II mileage data is that they are not recorded if the device is removed, the device malfunctions, or if the vehicle’s OBD-II data are not generated.

Alternative approaches. These approaches are not focused on deploying mileage recording approaches or technology and, thus, do not have implications for the accuracy, precision, reliability, or repeatability of mileage recording and fee reconciliation:

• Fleet-based:  The use of a shared-vehicle fleet’s ability to track mileage and location is central to the ability to assess a mileage fee under this approach being explored by Minnesota. To some extent, the approach is technology-agnostic and will rely on the fleet operator’s MRD technology to measure miles, to which a fee is then charged to the user.
• Registration fee-based:  As explored by Missouri, this approach will not consider miles driven, but rather will focus on backfilling transportation funding gaps caused by shortages in the motor fuel tax (MFT), with an additional graduated registration fee based on the vehicle’s fuel efficiency. In this scenario, driving behavior or miles driven does not inform the fee; therefore, there are no potential issues with accuracy, precision, reliability, or repeatability.

Ease of User Compliance Attribute: Transparency and Ability To Audit

The ability of the system to provide information on how the fee was assessed or will be assessed is the core essence of transparency. Knowledge of what the fee for a given amount of travel will be, changes in the fee while driving, and understanding how fees were calculated after driving has occurred are all mechanisms for maintaining transparency to drivers. This section explores the capabilities of the different systems and approaches explored in STSFA Phase Ⅰ for communicating this information to the driver.

The current MFT model is directly tied to the purchase of fuel, a necessity for the operation of almost all vehicles on the road today. As fuel is purchased prior to driving, there is no chance that a driver could accrue a tax bill for past driving. An RUC system, on the other hand, charges per mile instead of per gallon, which may lead to fees being billed well after driving has taken place. Depending on the billing cycle and number of miles driven, a driver could accumulate a relatively substantial bill to be paid separate from their purchase of fuel. The ability for a driver to understand the mileage fee and the ability for the driver to see the accumulation of those fees will be critical for maintaining transparency of the fee and how much drivers will owe.

Table 4 shows what information is explicitly available as part of the system. The information is divided into three types of trips—pre, intra, and post. A description of these trip types follows:

• Pre-trip transparency: In this scenario, drivers are aware of the fee, or actually pay a fee prior to the occurrence of the trip. This is divided into two data categories—fee and fee sum, which are described below.
• Intra-trip transparency: The system is able to communicate the fees being charged during the trip. This would include the per-mile fee, the trip fee, and the cumulative fee for road usage. When crossing jurisdictional boundaries with different rate structures, the system could communicate the fee structure to the driver.
• Post-trip transparency: A driver is able to see the history of where and when trips were made and how fees were accumulated from each of the trips. This is important for keeping track of fee accumulation prior to invoicing and for maintaining the ability to audit.

Each of the trip types is divided into data types. Not all data types will apply to each trip type. In any scenario, the driver could always use the vehicle odometer and the per-mile fee to calculate miles driven. For this evaluation, the following information should be available to the driver prior to invoicing:

• Fee: Will the incremental fee (per-unit fee) be visible to the driver? This information should consider cross-jurisdictional travel (i.e., a driver is aware of a change in fee when crossing national, State, or local jurisdictions).
• Fee sum: Will the cost of the trip or a cumulative running cost be visible to the driver?
• Miles: Will the system indicate the miles driven? (Only the odometer-based approach counts the vehicle’s odometer in this category.)
• Location: Will the system indicate where, specifically, fees and miles were accumulated?

Table 4. Visibility of data by trip type.

Type of Information	Pre-Trip		Intra-Trip		Post-Trip
	Fee	Fee Sum	Fee	Fee Sum	Fee	Fee Sum	Miles	Loc.
Motor fuel tax (for comparison)	Y						Y
Odometer (manual read)					Y	Y	Y
Image-based odometer					Y	Y	Y
Odometer/smartphone hybrid					Y	Y	Y	Y
Onboard diagnostic					Y	Y	Y
Smartphone with location	1	1	1	1	Y	Y	Y	Y
Plug-in device (onboard diagnostic standard II) with location					Y	Y	Y	Y
Fleet usage fee			2	2	2	2	2	2
Registration fee-based	Y	Y

Each of the trip types is divided into data types. Not all data types will apply to each trip type. In any scenario, the driver could always use the vehicle odometer and the per-mile fee to calculate miles driven. For this evaluation, the following information should be available to the driver prior to invoicing:

• Fee: Will the incremental fee (per-unit fee) be visible to the driver? This information should consider cross-jurisdictional travel (i.e., a driver is aware of a change in fee when crossing national, State, or local jurisdictions).
• Fee sum: Will the cost of the trip or a cumulative running cost be visible to the driver?
• Miles: Will the system indicate the miles driven? (Only the odometer-based approach counts the vehicle’s odometer in this category.)
• Location: Will the system indicate where, specifically, fees and miles were accumulated?

Odometer. This option communicates only the vehicle mileage to the driver, and the driver will need to either use the vehicle’s trip meter or record mileage before and after a set time period to determine mileage driven:

• Manual odometer reading: While a per-mile fee and cumulative fee may be readily known or calculated by the driver, it is not communicated by the system.
• Image-based odometer reading: Has a slight advantage over manual reading because it has an image record of the odometer reading for later reference and audit.
• Odometer/smartphone hybrid: Provides the added measurement and reporting of out-of-State driving. Out-of-State mileage is visible, post-trip, to the driver.

Onboard diagnostics non-location-based. Without location, the transparency of the mileage and fees of the OBD-II device is similar to an odometer reading. Drivers would have the ability to see cumulative mileage and fees post-trip, but the odometer would remain the best method of monitoring mileage while driving.

Location-Based Approaches

• Smartphone with location: The functionality of a smartphone increases with locational services activated, as it can allow the fee, the fee summary, and the location to be reported and viewed by the driver. The use of a smartphone also adds the potential to communicate information based on location (e.g., fees and total fees for a planned trip, and fees or total fees accumulated while driving).
• Plug-in device (OBD-II) with location: These devices are valuable in understanding past trips and the accumulation of fees and mileage, although the information will need to be accessed through the account manager’s online dashboard. The addition of locational services adds the ability to visually map where trips were taken and when, giving a high level of transparency for how fees were calculated and where mileage was driven.

Alternative Approaches

• Fleet-usage fee: This approach applies a fee to transportation fleets, such as car share or transportation network companies. These services typically rely on a smartphone to reserve a vehicle, plan a trip, monitor a trip, and manage payment and trip receipt. While the ConOps developed by Minnesota does not explicitly map out the availability of this information, and because the user interface and data will ultimately be controlled by the fleet operator, it is unknown at the time of this report what information will be available to the passenger and at what stage of the trip.
• Registration fee-based: Drivers are aware of the price prior to the trip. This approach requires a fee to be paid along with vehicle registration and based on the fuel efficiency of the vehicle. With this approach, mileage driven has no consequence on the fee paid. The need for intra- and post-driving information is not apparent, as driving behavior does not influence the fee.

Ease of User Compliance Attribute: Flexibility and User Choice

From a user perspective, there are two primary interactions that occur regularly with each of the proposed systems that will influence their ease of use—mileage reporting, including installation, operation, and maintenance of the mileage recording method or device; and payment of fees. For both of these interactions, the MFT system sets a baseline for ease of use for the passenger. The payment of fuel tax process is seamless and is inseparable from the purchase of fuel. There is a direct connection between the tax and the commodity necessary to operate the vehicle. For each of these categories of user actions, three metrics are explored:

• Required actions: The regularly occurring actions necessary for each of the concepts to function. For the purpose of this report, these are the actions that are critical to the operation of the mileage recording device/method, and the payment of fees. This list of actions is not intended to cover unplanned technology failure or other unanticipated situations.
• Additional effort: The required action of something that is already required of a driver, or an additional action that is required. For the purpose of this report, the comparison is between actions that are already required and will be newly required. For instance, the presence of a smartphone is necessary for several of the MRD concepts. Because a smartphone is not a requirement of driving a vehicle today, it would be considered a new requirement for the operation of the MRD. In general, actions that are already required will be more user friendly for passengers.
• Frequency of actions: An estimate of how often each of the actions for each of these concepts will be required by the driver. The less frequent the action, the less action required by the driver to manage the system.

Mileage Recording

The mileage recording methods and devices explored in the 2016 funding round of the STSFA Program and their associated, necessary user actions are presented in Table 5. For each of the concepts, the actions to operate have been outlined and are taken either specifically or inferred from the materials provided or from on-the-ground observations of the evaluation team. The intent is to outline how much effort is required from the user for the system to function correctly outside of any normal actions typically taken.

Of the concepts shown in Table 5, the only mileage recording method requiring minimal additional effort is the manual odometer reading, so long as that task is already required as part of a Department of Motor Vehicles (DMV) inspection. Generally, those MRD approaches that utilize a driver’s smartphone will require more actions and with a higher frequency. With the image capture, a smartphone is used monthly to capture and send an image of the odometer. For the smartphone approach with location, the presence of the driver’s phone that has power and is switched on must be continuous, in addition to the image capture of the odometer. Of the methods that need additional effort to operate, the plug-in MRD device has a relatively low level of effort from the driver and should require only the installation of the device.

Table 5. Mileage recording methods and associated user actions, additional effort, and frequency of actions.

Method	Mileage Recording Approach	Necessary User Actions To Operate	Additional Effort	Frequency
Odometer-based	Odometer (manual)	Requires regular visits to license agency for manual odometer reading.	No	Yearly
	Image-based odometer reading	Requires user to regularly photograph their odometer and send to account manager.	Yes	Monthly
	Odometer/smartphone hybrid	Requires user to regularly photograph their odometer and send to account manager.	Yes	Monthly
		Requires smartphone to be present in the vehicle, powered, and switched on.	Yes	Continuous
		May require a manual reading periodically to verify mileage.	Yes	Yearly
	Onboard diagnostic(OBD-II)-based	Requires installation of plug-in device into OBD-II port.	Yes	Once
Location-based	Smartphone with location	Requires smartphone to be present in the vehicle, powered, and switched on.	Yes	Continuous
		Requires installation of a Bluetooth beacon in vehicle.	Yes	Once
		May require a manual reading periodically to verify mileage.	Yes	Yearly
	Plug-in device (OBD-II) with location	Requires installation of plug-in device into OBD-II port.	Yes	Once

Payment of Fees

The second primary touchpoint from a user’s perspective is the payment of fees. In general, those actions that are incorporated into an existing payment will be easier to use for the driver. Examples include California’s pay-at-the-pump concept, Minnesota’s fleet-usage fee, and Missouri’s registration fee-based approach. In each of these examples, an existing payment is being made for fuel, rides, or vehicle registration, and the additional fee is incorporated into the payment. These approaches to payment are similar to the MFT, as the fee is being applied to an existing cost and becomes part of the cost of operation or use:

• Odometer reading through a DMV will typically occur yearly or twice per year, but payment can be estimated and broken down into smaller payments. If payment is done at the time of the reading, it would not be considered an additional effort, but if it is broken down into quarterly or monthly estimates, it would be considered an additional payment that is outside of today’s system.
• For all of the automated and semi-automated MRDs and mileage recording methods, the payment will typically be handled by a third-party account manager or by the State. In each case, an invoice is generated at a regular interval after driving has occurred, usually monthly. That invoice is sent to the driver to be paid. In these cases, there is additional effort, although different account managers may offer services like automatic payment withdrawal from a bank.

Table 6 provides a summary of payment methods associated with each mileage recording approach and the effort and frequency of associated user actions.

Table 6. Payment methods and associated user actions, additional effort, and frequency of actions.

Mileage recording approach	Necessary user actions to pay	Additional effort	Frequency
Pay-at-the-pump	Paid along with fuel bill	No	Per fueling
Fleet usage fee	Paid along with ride fee	No	Per ride
Registration fee-based	Paid along with vehicle registration fee	No	Yearly
Odometer reading	Paid along with vehicle registration fee	No	Yearly
	Monthly/quarterly estimates	Yes	Monthly/quarterly
Road usage charge mileage reporting device approaches	Invoice issued	Yes	Monthly1

The approaches that minimize the amount of actions, additional effort, or frequency will be more in line with the current gas tax system, which is the commonly cited baseline of user-friendliness and ease of use.