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CHAPTER 3 Selection and Description of Test Facilities 3.1 Selection of Facilities The study team started its pilot testing by identifying and discussing potential test facilities that already had completed CSMPs. As shown in Figure 3.1, there are roughly a dozen facilities in Southern California with CSMPs completed or underway. While not covering the entire freeway system in Southern California, these facilities cover many of the most congested routes in the SCAG region. After some discussion with SCAG and Caltrans staff, these were narrowed to nine potential test facilities in Los Angeles and Orange counties. Figure 3.1. Facilities with CSMPs in Southern California. The study team then researched the quality of the data available in PeMS and other sources reporting travel time reliability along the CSMP facilities. Table 3.1 provides a summary of the teamâs analysis of the potential pilot facilities. The table delineates the facility limits in terms of Caltrans postmiles and provides an indication of detection quality on the mainline freeway and adjacent high-occupancy vehicle lanes, if applicable. As shown in the table, most facilities have extensive detection with average detection spacing of less than one half mile. 25
Table 3.1. Analysis of Potential Pilot Facilities C al tra ns D is tri ct C ou nt y Fa ci lit y Fr om /T o Lo ca tio n Fr om A bs p .m . To A bs p .m . Mainline Detection High-Occupancy Vehicle Detection U se fu ln es s f or "U nr el ia bi lit y" o f T ra ve l Ti m e A na ly sis S um m ar y To ta l F ac ili ty D is ta nc e (m ile s) N um be r o f D et ec to rs b y D ire ct io n (N o r E /S o r W ) A ve ra ge D et ec to r S pa ci ng (m ile s/ de te ct or ) D at a Q ua lit y A ss es sm en t H ig h- O cc up an cy V eh ic le D is ta nc e (m ile s) N um be r o f D et ec to rs b y D ire ct io n (N o r E /S o r W ) A ve ra ge D et ec to r S pa ci ng (m ile s/ de te ct or ) D at a Q ua lit y A ss es sm en t 7 Los Angeles I-5 North I-10 to I- 210 132.7 160.7 28.0 41/50 0.7/0.5 ï¡ 6.0 6/3 0.8/1.2 â ï£ Long average spacing compared to other Facilities, poor data quality for both ML and high- occupancy vehicle. 7 Los Angeles I-5 South Orange County Line to I- 710 116.6 130.5 13.9 33/34 0.4/0.4 ï£ â Excellent spacing, but average data quality. No high- occupancy vehicle facility. Highly "unreliable" facility. 7 Los Angeles I-110 I-405 to Adams St 8.5 20.5 12.0 24/24 0.5/0.5 â 21.4 8/12 1.0/0.7 ï£ ï£ Good spacing and reasonable data quality for both ML and high-occupancy vehicle. 7 Los Angeles I-210 SR-134 to SR-57 24.6 44.9 20.3 40/43 0.5/0.5 â 20.3 39/42 0.5/0.5 â â Good spacing and reasonable data quality for both ML and high-occupancy vehicle. Highly "unreliable" facility. 7 Los Angeles I-405 North I-10 to I-5 53.7 72.1 18.4 25/32 0.7/0.6 ï¡ 8.3 12/24 0.7/0.6 ï¡ ï£ Long average spacing compared to other Facilities, poor data quality for both ML and high- occupancy vehicle. 7 Los Angeles I-405 South I-110 to I- 10 36.4 53.7 17.3 38/39 0.4/0.4 â 16.3 37/40 0.4/0.4 ï£ â Excellent spacing and good data quality. Highly "unreliable" facility. 12 Orange I-5 San Diego County Line to Los Angeles County Line 72.3 116.6 44.4 106/103 0.4/0.4 â 36.0 93/90 0.4/0.4 ï£ ï¡ Excellent spacing and very good data quality. Relatively "reliable" facility. 12 Orange SR-22 SR-55 to I-405 1.5 14.3 12.8 40/40 0.3/0.3 â 10.3 35/32 0.3/0.3 â ï¡ Excellent spacing and excellent data quality. Relatively "reliable" facility. 12 Orange SR-57 I-5/SR-22 to Los Angeles County Line 0.0 11.9 11.9 28/27 0.4/0.4 ï£ 11.2 31/27 0.4/0.4 ï£ â Good spacing, and reasonable data quality. 12 Orange SR-91 Riverside County Line to I- 5 18.0 37.2 19.2 37/35 0.5/0.5 ï£ 18.4 30/30 0.6/0.6 ï£ ï¡ Good spacing and reasonable data quality. Relatively "reliable" facility. 12 Orange I-405 I-5 to I-605 0.0 23.6 23.6 58/55 0.4/0.4 â 23.2 54/58 0.4/0.4 ï£ ï£ Excellent spacing, and very good data quality. Key: â High rank ï£ Medium rank ï¡ Low rank 26
