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20 TABLE 7 OPERATIONAL CATEGORIZATION OF ATCS BALANCE LA ATCS MOTION RHODES ACS Lite UTOPIA SCOOT SCATS InSync OPAC ATCS Detection SL, NSL NSL SL & NSL MB MB & SL, US US MB/ US & SL NSL, & SL & SL US SL MB Action P&R P&R P&R P&R P&R P P R P&R P Adjustment DCO TCO DCO RA, TCO TCO TCO RA DCO T CO TCO, DCO Time Frame 510 5 min Phase/ Cycle 515 Phase/ Sec by Cycle Cycle/ 3 sec min Cycle/ min Cycle/ sec 5 -- 15 5 min Cycle min min Level C/L C/L C/L C/L C/L C/L C/L C/L C/L C/L Model No Yes Yes Yes Yes Yes Yes No Yes Yes Timings S, O S, Cl, O, S, Cl, S, Cl, S, Cl, S, Cl, S S, Cl, S, Cl, S, PS PS O, PS O O, PS O O O, PS Flexi No No Yes Yes No No No Yes Yes Yes Region Vehicle Yes Yes No Yes Yes No No Yes Yes Yes Actuated TSP No Yes Yes Yes Yes Yes Yes Yes Yes Yes Detection: SL = stop-line; NSL = near-stop-line; MB = mid-block; US = upstream. Action: P = proactive; R = reactive. Adjustment: RA = rule-based adjustment; DCO = domain-constrained optimization; TCO = time-constrained optimization. Level: L = local; C = central. Timings: S = splits; Cl = cycle length; O = offset; PS = phase sequencing. and developers of ATCSs see their systems. One could also Software, Hardware, and Communications note that the categorization provided in Table 7 is based on information that is sometimes derived from limited systems' Table 8 provides examples of communications, software, descriptions in the literature. and hardware requirements for the ten ATCSs described in this study. A detail discussion of the principles presented in Table 7 is beyond the scope of this study; however, a few interesting SUMMARY observations are: In summary, this chapter provided an overview of the opera- High similarities of the operations of MOTION and tional characteristics of ten most-widely used ATCSs. Selected BALANCE reflect the concept that these two systems working principles were briefly described and ATCSs were were developed in a similar environment of local German categorized with emphases on their adaptive traffic control policies and standards. logics, systems' architectures, and detection requirements. RHODES, OPAC, and InSync are systems that do not The final sections of the chapter summarize, in tabular for- require local controllers to use their own actuated logic. mat, software, hardware, and communication requirements. SCATS is the only purely reactive system that does not The next chapter reports on institutional issues confronting use any traffic models (and yet it is one of the most widely most ATCS users, from installation through everyday opera- used ATCSs). tions and maintenance of ATCSs.

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21 TABLE 8 SOFTWARE AND HARDWARE SPECIFICATIONS FOR ATCS System Controller Software Communications ACS Lite Siemens NEMA (M50 ACS Lite software Comm: Serial or Ethernet. series) or 2070 (2002 running on field- Serial is single channel, TEES or later) with hardened PC or where 9600 baud supports up SEPAC NTCIP 4.01F central server to 8 signals. Faster serial can firmware. (Windows XP). support more signals. Also run with Econolite ASC/2 with NTCIP firmware w/ACS lite support. Peek 3000E with external NTCIP translator. McCain 170E with BI-TRAN 233 firmware with ACS Lite support. BALANCE European controllers GEVAS ISDN dial-up line VTnet/View 2400 bps-modem wireless InSync Existing Controllers Internet access to Ethernet communication Cabinets require InSync System InSync processor to through a local communicate with computer controller using detector cards InSync System LA ATCS Model 170 Controllers/ PC Dedicated central to field 172.3 Firmware ATCS/Traf Graph connection Type 2070 Controllers/ Editor 1200 bps using time division City of LA Software multiplexing 4 intersections/communication channel No Peer-to-Peer communication needed Supports multiple communication media MOTION SITRAFFIC C8xx,C9xx PC V34 modem Controllers SITRAFFIC Ethernet Signalbau Huber Actros Fiber-optic cable Controllers ... Older Siemens controllers Central control via wireless links using public communication channels such as Internet/GPRS OPAC Model 2070/multiple PC Dedicated central to field firmwares MIST connection at 9600 baud or Model 170 with 68360 higher Processor/multiple Peer-to-Peer possible through firmwares Central NEMA Controllers Supports all communications VME Bus or equivalent media RHODES 2070 ATC with RHODES Software Peer-to-Peer over Ethernet; NextPhase-Adapt on OS9/Windows/ Bandwidth 96000 bps. Controller Software Linux field-hardened, Supports all communications single-board computers media; preference is fiber optic. Econolite ASC/2 with Adapt X interface software (continued on next page)

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22 TABLE 8 (Continued) System Controller Software Communications SCATS Model 170 controllers with PC Requires 300 bps link to each SCATS conversion kit, SCATS controller using two-wire or which includes a new equivalent. processor board with Multidrop system is supported embedded software that requires a two-wire line or with 2070 or 2070 N equivalent to the first controllers with SCATS intersection in a cluster and proprietary controllers. then to each intersection in the NEMA AWA Delta 3N cluster in a daisy chain " controllers. There are configuration. several RTA type SCATS supports various approved SCATS configurations that can utilize controllers in current TCP/IP, leased line, and use sourced from conventional telephony Australia; i.e., Tyco services (i.e., dial-up). Eclipse, QTC, Aldridge ATSC/4, Tyco PSC and a myriad of legacy controllers still supported; e.g., Phillips PTF. SCOOT Eagle NEMA Eagle 2070/ PBS with MS Both SCOOT and ACTRA SEPAC support for 170 Windows Server 2003 require a separate channel to can be provided controller from the central-- at 9600 baud, 8 controllers can be supported. SCOOT algorithm Supports all communications and ACTRA media; wireless typically not used. UTOPIA Peek's EuroController with PC-based software MDSL unit Logic is distributed over control units.