Guide for Truck Parking Information Management Systems (2025)
Chapter: 6 Operating and Maintaining TPIMS
CHAPTER 6
Operating and Maintaining TPIMS
This chapter presents the requirements and options for operating and maintaining a TPIMS. Operating the TPIMS involves ongoing system monitoring and adjustment along with measuring performance and managing data. The resources required to operate the TPIMS will depend on the parking availability monitoring methodology and procurement strategy selected, which were discussed previously. This chapter shows how earlier decisions directly impact ongoing operations and maintenance needs. The following considerations are important for the operation and maintenance of a TPIMS:
- Operating Requirements.
- Reporting of Parking Availability.
- Methods for Capturing Performance Measures.
- Maintenance Requirements.
- Data Management and Archiving.
- Lifecycle Costs.
Transportation agencies need a comprehensive understanding of what is required to operate and maintain a TPIMS before deciding to implement a system. Without the resources to operate and maintain the system, the deployment’s return on investment will not be maximized, and the system may lose credibility with truck drivers, fall into disrepair, and be decommissioned. Establishing ongoing operations and maintenance practices and administrative oversight and support within the agency are often ongoing challenges for agencies with TPIMS.
Operating Requirements
Operating the system involves monitoring system components to ensure they are operational and resetting incorrect truck parking availability information when needed. Both the operations of the devices themselves and the operations of the system functions need to be considered.
Device Operations
The effort required to monitor device operations depends on the degree of automation associated with device malfunction reporting. For example, does the system recognize when a sensor has failed and report the failure to the appropriate staff? Tools within the data processing application can be implemented to monitor the system data for anomalies. The most basic example is monitoring the timestamp for the latest data at each truck parking site. If the difference between timestamps exceeds the typical reporting period, an alarm can be issued.
The reported parking spaces should be monitored for values below zero or values that exceed the parking area capacity. Other checks can assess the rate of change in the number of available
spaces to identify unreasonable increases and decreases between reporting periods. Operations or maintenance staff need to receive the system alarms and investigate if a real problem exists, typically by using surveillance cameras to observe the site. In the case of a communications outage, as with other ITS and technology equipment, site visits may be required to confirm malfunctions, which is discussed more in the maintenance section below. Given that truck parking demand typically peaks overnight, it is critical that an agency can receive and address alarms 24/7.
System Operations
During system operations, the transportation agency will need to verify that the information reported to the public is accurate. Risks to this accuracy often differ depending on the counting method employed:
- Entrance and Exit Counting. The number of available spaces will need to be reviewed, and the TPIMS parking availability counts will need to be updated when the reported availability is incorrect (Fallon and Howard 2011). This error has been found to propagate over time if the technology counting vehicles entering and exiting miscounts a vehicle since typically simple math is used to add and subtract each counted vehicle from the availability numbers. Advances in machine learning and algorithmic functions have been emerging to help correct when these errors occur, such as using video analytics to “check in” and “check out” vehicles virtually, in addition to detection. However, to date, there is no simple, reliable method other than having humans review and correct counting errors.
- Space Occupancy Counting. When parking space occupancy is directly monitored by technology, typical errors will correct themselves (Morris et al. 2017). A typical example is a truck that is parked close to the parking stall line that is detected as occupying two spaces. When the truck leaves, the error is corrected without needing manual intervention.
- Digital Occupancy and Crowdsourcing. While these methods may be employed by private facility owners or used by mobile application platforms, the data is generally not owned or managed by the transportation agency. If these methods are used, more caution is warranted to ensure quality and accuracy. There is an absence of public sector examples germane to the operations and maintenance of systems that use these types of sources.
To monitor for errors in parking availability, a person will need to manually observe the number of available parking spaces. Typically, an operator will use a surveillance camera at the truck parking area to remotely count the number of available spaces. The manual count is then compared to the availability of parking spaces reported by the system. If there is a difference in the count of available spaces, reported values must be corrected by the operator by manually inputting a correct value. The frequency of the required updates can vary from site to site, depending on the volume of trucks parking, number of driveways, and other factors. As sensor technology improves, the number of resets required will be reduced but likely will not be eliminated. See Figure 20 for an example illustration of remote observation by a TPIMS operator for updating parking space availability.
Additional methods of monitoring the “ground truth” are also emerging, such as using video analytics on a surveillance camera to perform a count of vehicles present; this has the potential to minimize the amount of manual intervention needed in the future. Commercial off-the-shelf machine vision software/hardware may be able to oversee other systems and provide count confirmation in the near future; CCTVs can be programmed on a regular “tour” to recognize the scene, identify the detection zones, and provide monitoring of that scene while at rest. The State of Ohio has been utilizing a software platform to automate the monitoring of parking spaces, and a system like this may also be utilized to perform verification counts (Parquery 2023).
Given the need for an operator to monitor the TPIMS and check accuracy at each parking site, support staff must be determined. Transportation agencies that have a systemwide operations center have typically tasked an existing operator to do the work. Careful consideration must be given to the impact on the existing workload of the operators. The tasks required of the operator(s) should be integrated into the operations center’s standard operating procedures.
Reporting of Parking Availability
As a parking area nears capacity, actual and perceived errors in the number of available spaces reported are more obvious to truck drivers. Actual errors, as discussed above, will occur. Perceived errors occur when a truck driver considers the number of available spaces to be more than just the marked spaces. Types of perceived errors include:
- Lot Capacity. When all marked spaces are filled, drivers may still consider the parking area to have capacity if trucks can be parked without impeding other trucks’ ability to enter or leave the parking area. This is an even bigger challenge with parking areas that do not have marked spaces where actual capacity can vary on a daily basis depending on how trucks are parked.
- Timing. The time lag between receiving availability information and actual parking. This is always a challenge when roadside signs are used to communicate availability. As discussed in Chapter 4, the roadside signs need to be placed upstream of the exit to a parking area to allow the driver to process the information and decide whether or not to park. There may be other trucks closer to the parking area that enter the site or parked trucks that leave before the driver arrives. Even if the number of available spaces is accurate, the truck driver can perceive the system as inaccurate when the number of spaces is different upon arrival. If there are many spaces available, this change will not be noticed. The extreme case would be if one space is reported to be available and a truck in front of the driver takes the space. When the driver arrives to park, there are no spaces, resulting in the system being perceived as inaccurate.
These ambiguities have resulted in agencies operating TPIMS reporting “Low” instead of a precise number as parking areas near capacity (MAASTO 2016). Reporting “Low” lets a truck driver know there is a risk that a space may not be available, but it does not provide an availability number that can be questioned. The threshold at which low is reported can vary based on the number of spaces, the amount of area available for informal parking, the methodology used to monitor availability, the accuracy of the technology, and how often the accuracy is monitored.
Methods for Capturing Performance Measures
A transportation agency will need to produce performance measures on how TPIMS operates, either in support of a grant requirement or to identify methods to improve the system. Critical system performance measures include system accuracy and system downtime:
- System accuracy should be measured by periodic comparisons of manually counted available truck parking spaces to the number of available spaces the system is reporting. The magnitude of required resets should be documented to provide data for tracking system accuracy. The accuracy data can be used to determine how often the site needs to be reset to meet minimum accuracy requirements.
- System downtime can be monitored at both the device level and the system level. Device outages should be tracked to help identify devices that need replacement. System downtime can be assessed at the system data level. Using the timestamped data, gaps in data availability can be calculated and cumulative downtime tracked. The transportation agency will need to decide what tools are needed to produce the data used in the performance measures.
Data from the TPIMS can also be used for performance measures that help document the value of the system and help with planning for parking site expansion. Before and after parking area utilization data can be used to demonstrate that the TPIMS is resulting in more efficient use of available truck parking spaces. Along a corridor with a TPIMS deployment, utilization will ideally balance out between parking areas to some extent. The system will bring awareness to parking areas with available spaces that drivers may not have known or used. Providing information for when a facility may not have capacity both alleviates the time spent trying to find a space and reduces the use of overloaded parking areas.
If the truck parking monitoring methodology or the sensor technology used to monitor parking utilization can also determine the number of trucks parked in non-designated spaces, excess demand can be documented. If the entrance/exit counting methodology is used, the system will document the total demand for the parking area even when it exceeds the marked space capacity. Technology monitoring space occupancy could also be designed to monitor areas without marked spaces, but this would require additional equipment. The ability to collect comprehensive parking demand data can be very useful in advocating for additional funding for increasing the number of truck parking spaces and determining where parking capacity should be added.
Surveys of truck drivers and dispatchers have also been used to collect information on the benefits of the system and how well it is working (I-10 Corridor Coalition 2020). Before and after deployment surveys can be used to assess the impacts of the TPIMS system.
Recognize Maintenance Requirements
A TPIMS has field devices, communications links, and central software that require maintenance. The installed sensor type may or may not require routine maintenance. Sensor technology that uses cameras will require periodic dome or lens cleaning to remove dust and salt. Other sensors, such as certain radar devices and magnetometers, do not require regular routine maintenance. Most in-pavement sensors are powered by internal batteries. Battery strength must be monitored, and the sensors must be replaced when batteries fail. Field cabinets housing sensor interfaces and communications network gear will require periodic filter replacement. Parking area surveillance cameras will require routine cleaning of the dome or lens. The typical maintenance associated with truck parking availability signs will be filter replacement in the adjacent equipment cabinet.
- Maintenance is required for both field equipment and back-office systems. Field equipment is vulnerable to damage by the environment, vehicle impacts, and vandalism, to name a few examples. A work order system is beneficial to document needed repairs and the timeliness of the repairs to facility maintenance, as well as valuable data for proactive lifecycle asset management. Back-office maintenance will be required to maintain security and compatibility with application and operating system upgrades.
- The transportation agency will need to determine if maintenance activities are completed by in-house staff or a private contractor. A private contractor will typically be paid for predefined routine maintenance activities and emergency maintenance activities to address equipment malfunctions. Since the system devices and maintenance activities are very similar to traditional ITS devices, the maintenance responsibilities could be undertaken by the entity currently doing the ITS maintenance.
- Other maintenance activities may also impact a TPIMS. For instance, if there is a maintenance project to mill and overlay the truck parking area and access driveways, any in-pavement sensors will need to be replaced. Likewise, any reconfiguration of spaces may result in the need to adjust the occupancy detection system. New within-agency coordination protocols will also need to be established so that maintenance projects address the impact and needed mitigation for TPIMS sensors.
Procurement and Management of Operations and Maintenance Contracts
If an agency decides to contract for operations and maintenance services for their TPIMS, it must determine who within the agency will manage the contracts and the length of the contracts. Managing the contract entails oversight, monitoring the contractor’s performance, and processing the contractor’s invoices. If the contract includes daily monitoring of system operations, they should be required to provide reports of system accuracy and downtime. The agency also needs to have the ability to periodically do their own accuracy check to validate the contractor’s reporting. Contractors responsible for maintenance must be required to document and report their maintenance activities, such as through a work order tracking system.
When determining the length of contract for operations or maintenance contracts an agency must balance the effort of the procurement process with the ability to change contractors that are not performing as expected. Structuring a contract to have performance option years can help manage the risk. Agency procurement requirements will also impact the selected contract length.
The Iowa DOT TPIMS deployment contract included operations and maintenance of the system for a three-year period, and it required periodic meetings and system status reporting (Iowa Department of Transportation 2017). The contractor selected for the deployment, operations, and maintenance was required to hold monthly project review meetings during the operations and maintenance period. The contractor organized the meetings, provided agendas, provided meeting notes, and tracked action items. The monthly reports documented system accuracy and system downtime, which were used to calculate contractor payments for each month.
Plan for Data Management and Archiving
A TPIMS will generate a significant amount of data. Depending on funding requirements or agency policy, data may need to be stored and/or shared with other groups, which requires proper data management and archiving. As discussed earlier, the system data is needed for calculating performance measures. The TPIMS data can also be very useful for freight planning activities, including truck parking studies.
A transportation agency will need to decide how long the raw data should be saved. Based on the majority of deployments today, data will be generated at least every five minutes for each site, 24 hours a day, every day. Additionally, a transportation agency will need to decide how data should be shared with others, such as through manual processes or through the development of a data query application that allows data to be extracted by researchers. Individual agency data access policies must be taken into consideration when determining how data will be shared.
For multistate deployments, continued coordination is required across states for planning, infrastructure and technology, and data management.
Lifecyle Costs
TPIMS deployments are relatively new, so there is limited TPIMS-specific lifecycle cost data. Fortunately, the lifecycle costs for TPIMS are expected to be very similar to other ITS deployments. The components of a TPIMS are identical or very similar to other ITS implementations. Typical costs for routine and malfunction maintenance will be incurred for the TPIMS components.
Additional costs include personnel responsible for site accuracy checks and manual updates as well as multistate coordination. To estimate the lifecycle costs for the system, it should be assumed the operator will only be periodically completing TPIMS tasks. For systems using the entrance/exit counting methodology, a reasonable assumption is that an operator will need to spend ten minutes per site twice a day every day of the week reviewing each site and updating the truck parking availability. For a system monitoring space occupancy, a reasonable assumption is the site should be manually checked once a week for ten minutes per site.
