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1. How many lanes of traffic does the system support?

Depending on their distance from the roadway, the sensors can measure speeds in up to four lanes of traffic. Since the system uses the average speed of traffic to select messages and speeds don’t vary much between lanes, it’s not critical that the sensor gathers data from every lane. For this reason we state that the system can be used on roadways up to four lanes wide.

2. Can the sensors be directed so as to measure speeds in a single direction (e.g., for use in a two-lane bi-directional application?

Yes, the sensors have an internal switch that determines whether the sensor measures speeds of approaching or receding vehicles.

3. How would one handle location of the ADAPTIR™ equipment in an emergency scenario, such as a major traffic accident where traffic queues may continuously spread farther upstream?

In order for the system to operate correctly, at least one speed sensor (on an S3R or VMS) must be far enough upstream that it detects free-flow speeds. In the event traffic queues extend upstream to the last sensor, it must be moved. The system will trigger a dial-out alarm in the event speeds at the sensor farthest upstream drop to 35 mph.

4. What is the delay prediction algorithm?

When building a configuration file for a given site, the operator must specify the location of each piece of equipment along the roadway. ADAPTIR™ treats the roadway as a series of contiguous segments, where a segment is defined as a stretch of roadway with a speed sensor at each end. The system knows the speed at each end of the segment (from the sensors) and the length of the segment (the distance between the sensors, from the configuration file). A (weighted) average speed for the segment is calculated and divided into the length of the segment to derive the time required to traverse the segment. This process is repeated for each segment allowing the total time to traverse the roadway to be calculated by adding-up the segment times. This total time is compared to the value obtained by assuming that motorists could traverse the entire instrumented segment at free-flow speed. The excess of the total of the segment times versus the free-flow time represents the delay.

5. Has the accuracy of the algorithm been determined?

The accuracy of the algorithm itself is intrinsic in its design and is being evaluated as part of the system evaluation in Kentucky and Nebraska. However, the accuracy of the sensors also contributes to delay prediction accuracy. In cursory testing, the sensors measured speed to within 2-3 mph.

6. How, as a driver, do I know that the time displayed in a VMS time-stamp message applies to today?

Discounting variations in the setting of individual watches, the time on VMS message should be within five minutes of the current time, strongly implying that the corresponding delay or speed advisory message is current. Unfortunately, portable VMSs are limited to three lines of eight characters precluding a more detailed time-stamp message.

7. If ADAPTIR™ could be deployed in a two-lane, bi-directional application, could the system handle a configuration for each direction? If so, how close must each configuration be?

Yes,ADAPTIR™ can easily handle such a case. The system is designed to operate at least two independent work areas simultaneously. In order to operate two independent work areas, at least one RRS from each work area must be within direct communications range of the CSC. This can be achieved through the use of S3Rs (as repeaters) if necessary.

8. How much time is generally needed to initiate system operation?

Not counting the time needed to haul the equipment to the site, the field units can be deployed along the roadway in less than half an hour each. An experienced operator might spend another two hours to deploy the CSC, erect its antenna and build the work zone’s configuration file. Note this process could be performed concurrently with the field equipment deployment.

9. Will different passwords be supplied to different jurisdictions?

If asked for, Scientex can provide different passwords for different users.

10. In the event the CSC is unable to restore communications causing the system to shut down, what is the backup position? Doesn’t this possibility imply that passive work zone signs be in place thereby increasing traffic control costs?

Each time the system is initialized, the CSC loads every VMS and HAR with a default message to be used when the system is inactive. This message can be BLANK or something like SYSTEM UNDER TEST at the customer’s discretion. Once the system is activated, should any RRS controlling a VMS or HAR fail to "hear" the CSC for a specific period of time, the RRS will assume the system has shut down unexpectedly and load its default message into the VMS or HAR. Since no system like ADAPTIR™ can be totally reliable, passive signing, as required by the MUTCD for the foreseeable future are still required.

11. Will Operator’s Manuals be available to show color-coded delay and speed bars etc.? Can a color-defining sticker be provided for attachment to the side of the CSC?

ADAPTIR™ Owner’s Manual will be provided. A sticker as described will be provided to any customer who requests one.

12. How much voltage is required to operate an RRS and speed sensor? When a low voltage warning is given, how much time would an operator have to recharge the equipment shuts down?

The current RRS and speed sensor will operate well below 11 volts though the radio modem’s power output (and, therefore, communications range) is degraded below 11 volts. The low voltage warning threshold will be determined empirically in the field so as to allow a day or two of operation before shutdown.

13. How many daily log files can be stored before they must be downloaded? How many days of log files do States want for protection in case of possible legal actions concerning messages displayed by ADAPTIR™ ? How easy will it be to review a downloaded log file?

ADAPTIR™ log files are stored on the CSC’s hard drive. The smallest hard drive you can get these days has a capacity of one-gigabyte (1024 megabytes). On a really busy day or one with lots of communications problems, the system’s log files together might total on the order of 100,000 bytes (.1 megabyte). This implies that a one-gigabyte hard drive could store >20 years of ADAPTIR™ log files. This should be adequate. Since the log files are standard DOS text format files they can be viewed or printed from DOS (edit or print) and Windows (notepad or any word processor that can import text files (all of them)).

14. What is the suggested wording of the lane control message if there are four lanes in one direction?

    Any appropriate lane control message to be used is entered by the operator during the building of the work zone configuration file.

15. Will customers own rights to ADAPTIR™ software?

    No, the customer is buying the right to use the ADAPTIR™ software, not the software itself. Furthermore, the customer does not have rights to the source code from which theADAPTIR™ software is produced.

16. Does the ADAPTIR™ wireless communications sub-system require a license from the FCC to operate?

    Yes. As part of theADAPTIR™ system, Scientex will obtain the necessary license for the client.

17. How do we know if VMSs from a customer’s inventory are compatible with ADAPTIR™?

    To be compatible with ADAPTIR™, a VMS must be capable of being controlled remotely. This is typically accomplished via a cellular phone connection and modem. While ADAPTIR™ compatibility does not require the VMS to have a cellular phone interface, the VMS must have an RS-232 port (again, typically for a modem). Furthermore, each VMS and HAR manufacturer implements a proprietary communications protocol ("language") for remote control. Some manufacturers (e.g., ADDCO) have more than one protocol. In order to work with ADAPTIR™, a client’s VMS and HAR must either implement one of the protocols already supported by ADAPTIR™ or the client must provide the vendor’s protocol to us. ADAPTIR™ currently supports ADDCO model DH 1000 and DM 1100 VMSs, Precision Solar Model T-321, Display Solutions Nitehawk Gen VI cellular VMSs, and ISS HARs. If the customer wishes to use other equipment, Scientex will implement the new protocol in ADAPTIR™. 

18. What is the minimum communications range Scientex will guarantee?

    Due to the impossibility of anticipating the topographic and ambient RF noise characteristics of every site at which ADAPTIR™ might be used, Scientex cannot guarantee a communications range between successive RRSs or between RRSs and the CSC. Typically communications range between units is ~2-3 miles on level open terrain. Scientex recommends deploying the RRSs and traffic sensors at roughly one-mile intervals along the roadway to insure adequate speed data coverage. Additional S3Rs can be deployed as repeaters in cases where topography/terrain/traffic-engineering issues force RRS deployment beyond direct communications range.

19. Can Scientex use a customer-supplied PC for the CSC?

    No. The CSC is sold as a bundled unit consisting of a PC integrated with a radio modem, telephone modem, and dial-out alert system. Due to ADAPTIR™ warranty obligations and the impact of an unreliable PC on system operations, Scientex will not consider building a CSC on a customer-supplied PC. Typically the CSC’s PC represents only ~1/2 percent of the system cost.

20. When operated in a work zone with closed lanes, does ADAPTIR™ require specification of which lanes are closed?

    Yes. This information is entered during the configuration (.wad) file creation though it is used only to generate the graphical depiction of the work area in the Observe Work Area display. During the configuration file creation process, the operator can enter a custom lane closure, speed, delay, and diversion message for display by the system’s VMSs.

21. Is seven the maximum number of VMSs that could be used?

    At the moment, the system supports the use of up to two VMSs (shoulder and/or median) at each of seven locations. This limitation arises strictly due to cosmetic issues associated with displaying the VMSs’ messages in real-time on a single screen. If seven VMS locations are not sufficient, the system’s user interface software can be modified to accommodate more VMSs. The system’s data acquisition and control hardware and software can currently accommodate more than 100 VMSs.

22. Is ADAPTIR™ Y2K compliant?

    Yes.

23. What performance limits apply to severe weather conditions?

    ADAPTIR™’s roadside equipment is guaranteed to operate over a temperature range of -30° C (-22° F) to +60° C (+140° F). Due to their method of acquiring speed data (e.g., Doppler radar), the accuracy of the system’s sensors is not subject to degradation due to inclement weather.

24. Who is the MSHA contact for the WZTCS research project?

    Mr. Tom Hicks; Director, Office of Traffic and Safety; 410-787-5815

25. Could we connect cameras to our system?

    Yes, the current system configuration can be easily modified to support cameras. If needed, the modular design of the ADAPTIR™ software can be updated to include a video feed.

26. What is the current draw from the VMS or Arrow panel due to additional ADAPTIR™ equipment?

Conservatively approximated the RRS and the sensors draw a total current of 600 milliamps.

If you have any additional questions please send us an e-mail at adaptir@scientexcorp.com