2.0 TRANSIT ROUTES AND PARK-AND-RIDE LOTS
2.1 Data Sources
The tolling system used on the I-394 MnPASS project will be used on the I-35W HOT lanes and the PDSL. As a result, the tolling test plan builds on the data collection and analysis process in place on the I-394 MnPASS project. More detail on the MnPASS data is presented below. Data from the Minnesota State Patrol on violations of the MnPASS operating requirements will also be obtained and analyzed. Additional information needed for the tolling analysis will be obtained from the traffic system data test plan.
MnPASS Database. Individuals may open accounts with MnPASS on-line, over the telephone, or at the customer service center. The MnPASS system operator assigns individual transponders to account holders. The transponders are mounted via a cradle on the vehicle windshield. When the transponder is connected to the cradle, transactions may occur between the roadside toll collection systems; conversely, when the transponder is disconnected from the cradle, transactions are impeded. This approach is necessary to provide drivers with the ability to use the MnPASS HOT lanes either as a toll-paying, single-occupant vehicle or as a non-tolled high-occupancy vehicle.
For each toll transaction (with multiple transactions per trip), the following data are written by the system to the transponder for transmission to the revenue and accounts management system:
- data and time of transaction;
- transponder identification number; and
- roadside toll collection identification number.
After the system receives the data, the transactions are processed to determine the full trip (with each transaction appended to one another to reflect a corridor trip), with tolls applied based upon the established rate at the point of entry. As such, the account transaction reflects precise date, time, and toll charge for each toll segment.
Quarterly reports are provided to Mn/DOT by the system operator on the I-394 project. Table 2-1 presents the information provided in the quarterly reports. Figure 2-1 illustrates one example of how the data are presented in the quarterly reports. Daily individual transaction level data are available and will be provided to the Battelle team for the I-35W HOT lanes and the PDSL. In addition, data on MnPASS transponder purchases and returned transponders will be provided on a monthly basis. The system operator will also provide the zip codes of MnPASS transponder holders, the vehicle model, and individual registering commercial vehicles on a monthly basis. Data on the frequency of transaction use by zip code, vehicle model, and commercial vehicle will be provided on a quarterly basis.
Minnesota State Patrol. Information from the Minnesota State Patrol on the number of citations issued for violation of the HOT operating requirements will also be obtained and evaluated. Possible violations include vehicles with no MnPASS transponder, vehicles with an invalid MnPASS transponder, and vehicles illegally entering and exiting the HOT lanes and PDSL. Table 2-2 provides an example of how this data will be summarized. Information will be requested on a monthly basis, but it is realized that there is often a lag time in receiving data from the State Patrol.
|Type of Data|
Accounts and Transponders
Customer Service Center
Network and Systems
Figure 2-1. Example of Data Presented in MnPASS Quarterly Report
|Type of Violation||Number of Citations|
|Illegally Entering/Exiting HOT/PDSL|
2.2 Data Availability
As noted, the toll data will be obtained from Mn/DOT and the MnPASS service provider. The needed data is currently being collected and provided on the I-394 MnPASS project. There is no pre-deployment toll data for I-35W. As discussed in Section 4.0, post-deployment data collection will be initiated after implementation of the initial HOT lane segment and the PDSL in October 2009. It is anticipated that the daily MnPASS data will be batched and transmitted to the Battelle team on a monthly basis.
2.3 Potential Risks
There do not appear to be any significant risks associated with obtaining the MnPASS data from Mn/DOT and the MnPASS service provider or the violation data from the Minnesota State Patrol. These data are currently being provided on the I-394 MnPASS project, so the procedures for collecting and maintaining these data are well established. The experience from I-394 indicates that one problem that may be encountered periodically is that the MnPASS tolling services may not receive updated traffic data from Mn/DOT's road sensors, which causes the MnPASS pricing to default to the rate tables. However, on I-394, these issues have been addressed quickly and have not caused major problems for providing the needed data. As a result, the risk that significant data for the toll analysis on I-35W will be lost is judged to be low. Thus, no special efforts to address the low risk are recommended.