Simulator Study of Signs for A Complex Interchange and Complex Interchange Spreadsheet Tool

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APPENDIX C. DESCRIPTION OF SURVEY SITES USED IN DEVELOPING THE SPREADSHEET TOOL

This appendix contains descriptions of each of the 28 interchanges used in developing the complex interchange spreadsheet tool. The descriptions each contain an aerial photograph, a brief description of the interchange's location and routes, and a summary of the characteristics used in the spreadsheet.

Information for site AZ-1 is as follows:

• Site: AZ-1.
• Location: Phoenix, AZ.
• Primary route: I-10.
• Secondary/intersecting routes: I-17/US-60.

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Figure 80. Photo. Aerial view of site AZ-1. ⁽⁵⁰⁾

Table 49. Characteristics of AZ-1.

Variable	NB	SB	EB	WB
Study length (ft)	9,010	9,590	13,755	12,665
Number of concurrent routes	2	2	1	1
Number of levels	4	4	4	4
Number of missing movements	0	0	0	0
Number of ramps	4	4	5	4
Exit ramps per mile	1.17	1.10	1.15	0.83
Entrance ramps per mile	1.17	1.10	0.77	0.83
Left exits per mile	0.00	0.00	0.00	0.00
Left entrances per mile	0.00	0.00	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.59	0.55	0.00	0.42
Multilane exit ramps per mile	0.59	0.55	0.38	0.42
Optional/shared exit lanes per mile	0.59	1.10	0.77	0.42
Exit only lanes per mile	1.17	1.10	0.77	0.83
Score	355	505	490	470
Overall score	455

Information for site AZ-2 is as follows:

• Site: AZ-2.
• Location: Phoenix, AZ.
• Primary routes: I-10 and SR 51.
• Secondary/intersecting routes: SR 51 and LP 202.

©2011 Google Earth^®
Figure 81. Photo. Aerial view of site AZ-2. ⁽⁵¹⁾

Table 50. Characteristics of AZ-2.

Variable	NB	SB	EB	WB
Study length (ft)	9,450	10,555	5,555	10,455
Number of concurrent routes	1	1.125	1	1
Number of levels	4	4	4	4
Number of missing movements	0	0	0	0
Number of ramps	4	8	2	7
Exit ramps per mile	1.68	1.50	1.90	1.52
Entrance ramps per mile	0.56	2.00	0.00	2.02
Left exits per mile	0.56	0.50	0.95	0.51
Left entrances per mile	0.00	1.00	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.00	0.95	1.01
Multilane exit ramps per mile	0.56	0.50	0.95	0.00
Optional/shared exit lanes per mile	1.68	0.50	1.90	0.00
Exit only lanes per mile	0.56	1.50	1.90	1.52
Score	440	605	370	620
Overall score	508.75

Information for site AZ-3 is as follows:

• Site: AZ-3.
• Location: Prescott, AZ.
• Primary route: I-17.
• Secondary/intersecting route: SR 69.

©2011 Google Earth^®
Figure 82. Photo. Aerial view of site AZ-3. ⁽⁵²⁾

Table 51. Characteristics of AZ-3.

Variable	NB	SB	EB	WB
Study length (ft)	46,355	46,360	6,945	4,305
Number of concurrent routes	1	1	1	1
Number of levels	2	2	2	2
Number of missing movements	0	0	0	0
Number of ramps	2	4	2	2
Exit ramps per mile	0.11	0.23	0.76	1.23
Entrance ramps per mile	0.11	0.23	0.76	1.23
Left exits per mile	0.00	0.00	0.00	0.00
Left entrances per mile	0.00	0.00	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.11	0.00	0.00	0.00
Multilane exit ramps per mile	0.00	0.00	0.00	0.00
Optional/shared exit lanes per mile	0.11	0.11	0.00	1.23
Exit only lanes per mile	0.00	0.11	0.76	0.00
Score	154	230	270	300
Overall score	236.25

Information for site DE-1 is as follows:

• Site: DE-1.
• Location: Wilmington, DE.
• Primary route: I-95.
• Secondary/intersecting routes: SR 1/SR 7 and Churchmans Road.

©2011 Google Earth^®
Figure 83. Photo. Aerial view of site DE-1. ⁽⁵³⁾

Table 52. Characteristics of DE-1.

Variable	NB	SB	EB	WB
Study length (ft)	6,300	6,642	16,405	19,255
Number of concurrent routes	2	2	1	1
Number of levels	2	2	2	2
Number of missing movements	0	0	0	0
Number of ramps	5	3	4	3
Exit ramps per mile	2.51	0.79	0.64	0.55
Entrance ramps per mile	1.68	1.59	0.64	0.27
Left exits per mile	0.00	0.00	0.00	0.00
Left entrances per mile	0.00	0.00	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.79	0.00	0.27
Multilane exit ramps per mile	0.00	0.79	0.00	0.00
Optional/shared exit lanes per mile	0.84	0.79	0.00	0.00
Exit only lanes per mile	1.68	0.79	0.64	0.55
Score	375	325	170	170
Overall score	260

Information for site DE-2 is as follows:

• Site: DE-2.
• Location: Wilmington, DE.
• Primary routes: I-95/I-295.
• Secondary/intersecting routes: US-202/SR 141.

©2011 Google Earth^®
Figure 84. Photo. Aerial view of site DE-2. ⁽⁵⁴⁾

 

Table 53. Characteristics of DE-2.

Variable	NB	SB	EB	WB
Study length (ft)	4,855	3,625	10,320	17,405
Number of concurrent routes	2	2	1	1
Number of levels	2	2	2	2
Number of missing movements	0	0	1	0
Number of ramps	5	4	2	3
Exit ramps per mile	2.18	4.37	0.51	0.30
Entrance ramps per mile	3.26	1.46	0.51	0.61
Left exits per mile	1.09	1.46	0.00	0.00
Left entrances per mile	0.00	0.00	0.51	0.30
Number of exit ramps with multiple destinations per mile	0.00	0.00	0.51	0.30
Multilane exit ramps per mile	0.00	0.00	0.51	0.30
Optional/shared exit lanes per mile	1.09	2.91	0.51	0.00
Exit only lanes per mile	1.09	1.46	0.51	0.61
Score	465	435	335	420
Overall score	413.75

Information for site DE-3 is as follows:

• Site: DE-3.
• Location: Wilmington, DE.
• Primary route: I-295.
• Secondary/intersecting routes: SR 13/US-40.

©2011 Google Earth^®
Figure 85. Photo. Aerial view of site DE-3. ⁽⁵⁵⁾

Table 54. Characteristics of DE-3.

Variable	NB	SB	EB	WB
Study length (ft)	3,085	1,990	10,010	9,180
Number of concurrent routes	2	2	1	1
Number of levels	2	2	2	2
Number of missing movements	0	0	0	0
Number of ramps	5	4	4	3
Exit ramps per mile	1.71	5.31	1.05	0.58
Entrance ramps per mile	6.85	5.31	1.05	1.15
Left exits per mile	1.71	2.65	0.00	0.00
Left entrances per mile	5.13	2.65	0.53	0.58
Number of exit ramps with multiple destinations per mile	0.00	2.65	0.00	0.58
Multilane exit ramps per mile	1.71	0.00	0.00	0.58
Optional/shared exit lanes per mile	1.71	0.00	0.00	0.00
Exit only lanes per mile	1.71	5.31	1.05	1.15
Score	465	465	360	390
Overall score	420

Information for site GA-2 is as follows:

• Site: GA-2.
• Location: Atlanta, GA.
• Primary routes: I-85/SR 403.
• Secondary/intersecting route: I-285.

©2011 Google Earth^®
Figure 86. Photo. Aerial view of site GA-2. ⁽⁵⁶⁾

Table 55. Characteristics of GA-2.

Variable	NB	SB	EB	WB
Study length (ft)	12,215	12,090	11,530	9,065
Number of concurrent routes	2	2	1	1
Number of levels	3	3	3	3
Number of missing movements	0	0	0	0
Number of ramps	4	4	4	3
Exit ramps per mile	0.86	0.87	0.92	0.58
Entrance ramps per mile	0.86	0.87	0.92	1.16
Left exits per mile	0.00	0.00	0.00	0.00
Left entrances per mile	0.00	0.00	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.43	0.44	0.46	0.00
Multilane exit ramps per mile	0.43	0.87	0.92	0.00
Optional/shared exit lanes per mile	0.43	0.87	0.46	0.00
Exit only lanes per mile	0.86	0.87	1.37	0.58
Score	415	415	350	300
Overall score	370

Information for site GA-3 is as follows:

• Site: GA-3.
• Location: Atlanta, GA.
• Primary routes: I-85/SR 403.
• Secondary/intersecting route: SR 316.

©2011 Google Earth^®
Figure 87. Photo. Aerial view of site GA-3.⁽⁵⁷⁾

Table 56. Characteristics of GA-3.

Variable	NB	SB	EB	WB
Study length (ft)	17,450	16,095	8,285	13,920
Number of concurrent routes	2	2	1	1
Number of levels	2	2	2	2
Number of missing movements	0	1	0	0
Number of ramps	4	4	2	4
Exit ramps per mile	0.91	0.33	0.00	1.52
Entrance ramps per mile	0.30	0.98	1.27	0.00
Left exits per mile	0.30	0.00	0.00	0.76
Left entrances per mile	0.00	0.33	0.64	0.00
Number of exit ramps with multiple destinations per mile	0.30	0.00	0.00	0.00
Multilane exit ramps per mile	0.61	0.00	0.00	0.00
Optional/shared exit lanes per mile	0.61	0.00	0.00	0.76
Exit only lanes per mile	0.91	0.33	0.00	0.76
Score	435	250	200	380
Overall score	316.25

Information for site GA-4 is as follows:

• Site: GA-4.
• Location: Macon, GA.
• Primary routes: I-75/SR 401.
• Secondary/intersecting routes: I-16/SR 404.

©2010 Google Earth^®
Figure 88. Photo. Aerial view of site GA-4. ⁽⁵⁸⁾

Table 57. Characteristics of GA-4.

Variable	NB	SB	EB	WB
Study length (ft)	5,810	12,025	2,400	8,680
Number of concurrent routes	2	2	2	2
Number of levels	2	2	2	2
Number of missing movements	0	0	0	0
Number of ramps	1	2	1	1
Exit ramps per mile	0.91	0.44	0.00	0.00
Entrance ramps per mile	0.00	0.44	2.20	0.61
Left exits per mile	0.00	0.44	0.00	0.00
Left entrances per mile	0.00	0.44	2.20	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.00	0.00	0.00
Multilane exit ramps per mile	0.91	0.00	0.00	0.00
Optional/shared exit lanes per mile	0.00	0.00	0.00	0.00
Exit only lanes per mile	1.82	0.44	0.00	0.00
Score	295	265	225	105
Overall score	222.5

Information for site IN-1 is as follows:

• Site: IN-1.
• Location: Gary, IN.
• Primary routes: I-80/I-94/US-6.
• Secondary/intersecting route: I-65.

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Figure 89. Photo. Aerial view of site IN-1.⁽⁵⁹⁾

Table 58. Characteristics of IN-1.

Variable	NB	SB	EB	WB
Study length (ft)	16,330	15,650	24,575	10,605
Number of concurrent routes	1	1	3	3
Number of levels	2	2	2	2
Number of missing movements	0	0	0	0
Number of ramps	4	4	3	4
Exit ramps per mile	0.65	0.67	0.43	0.50
Entrance ramps per mile	0.65	0.67	0.21	1.49
Left exits per mile	0.00	0.00	0.00	0.00
Left entrances per mile	0.00	0.00	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.34	0.43	0.50
Multilane exit ramps per mile	0.32	0.00	0.21	0.50
Optional/shared exit lanes per mile	0.00	0.00	0.21	0.50
Exit only lanes per mile	0.97	0.67	0.43	0.50
Score	330	230	365	250
Overall score	293.75

Information for site IN-3 is as follows:

• Site: IN-3.
• Location: Indianapolis, IN.
• Primary routes: I-69/SR 37/Binford Boulevard.
• Secondary/intersecting routes: I-465/US-421/US-31.

©2010 Google Earth^®
Figure 90. Photo. Aerial view of site IN-3.⁽⁶⁰⁾

Table 59. Characteristics of IN-3.

Variable	NB	SB	EB	WB
Study length (ft)	5,105	6,605	18,015	17,915
Number of concurrent routes	3	2.5	3	3
Number of levels	2	2	2	2
Number of missing movements	1	0	0	1
Number of ramps	3	2	3	3
Exit ramps per mile	1.03	0.80	0.59	0.29
Entrance ramps per mile	2.07	0.80	0.29	0.59
Left exits per mile	0.00	0.00	0.00	0.00
Left entrances per mile	0.00	0.00	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.80	0.00	0.00
Multilane exit ramps per mile	0.00	0.80	0.00	0.29
Optional/shared exit lanes per mile	0.00	0.80	0.00	0.29
Exit only lanes per mile	1.03	1.60	0.59	0.29
Score	325	330	220	235
Overall score	277.5

Information for site IA-1 is as follows:

• Site: IA-1.
• Location: Des Moines, IA.
• Primary routes: I-80/I-35.
• Secondary/intersecting routes: I-235/I-35.

©2011 Google Earth^®
Figure 91. Photo. Aerial view of site IA-1.⁽⁶¹⁾

Table 60. Characteristics of IA-1.

Variable	NB	SB	EB	WB
Study length (ft)	15,105	15,775	18,159	17,100
Number of concurrent routes	1.333	1.333	1.25	1.25
Number of levels	2	2	2	2
Number of missing movements	0	0	0	0
Number of ramps	3	3	4	4
Exit ramps per mile	0.35	0.33	0.58	0.62
Entrance ramps per mile	0.70	0.67	0.58	0.62
Left exits per mile	0.00	0.00	0.29	0.31
Left entrances per mile	0.00	0.00	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.35	0.33	0.00	0.00
Multilane exit ramps per mile	0.35	0.33	0.00	0.00
Optional/shared exit lanes per mile	0.00	0.00	0.00	0.31
Exit only lanes per mile	0.70	0.67	0.58	0.31
Score	345	305	275	375
Overall score	325

Information for site IA-2 is as follows:

• Site: IA-2.
• Location: Cedar Rapids, IA.
• Primary routes: I-380/SR and 27/US-218.
• Secondary/intersecting routes: US-30/US-151/US-28.

©2010 Google Earth^®
Figure 92. Photo. Aerial view of site IA-2. ⁽⁶²⁾

Table 61. Characteristics of IA-2.

Variable	NB	SB	EB	WB
Study length (ft)	17,250	17,030	5,775	5,815
Number of concurrent routes	2	1.667	2	2.5
Number of levels	2	2	2	2
Number of missing movements	0	0	0	0
Number of ramps	4	3	4	4
Exit ramps per mile	0.61	0.31	1.83	1.82
Entrance ramps per mile	0.61	0.62	1.83	1.82
Left exits per mile	0.00	0.00	0.00	0.00
Left entrances per mile	0.00	0.00	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.31	0.00	0.00
Multilane exit ramps per mile	0.00	0.31	0.00	0.00
Optional/shared exit lanes per mile	0.31	0.31	0.00	0.00
Exit only lanes per mile	0.31	0.31	1.83	1.82
Score	255	245	295	270
Overall score	266.25

Information for site IA-3 is as follows:

• Site: IA-3.
• Location: Sioux Falls, IA.
• Primary route: I-29.
• Secondary/intersecting routes: I-129 and US-75/US-20.

 

©2010 Google Earth^®
Figure 93. Photo. Aerial view of site IA-3. ⁽⁶³⁾

Table 62. Characteristics of IA-3.

Variable	NB	SB	EB	WB
Study length (ft)	18,055	17,625	14,595	15,290
Number of concurrent routes	1	1	2.333	2.333
Number of levels	2	2	2	2
Number of missing movements	0	0	0	0
Number of ramps	4	2	2	3
Exit ramps per mile	0.58	0.30	0.72	0.35
Entrance ramps per mile	0.58	0.30	0.36	0.69
Left exits per mile	0.00	0.00	0.00	0.00
Left entrances per mile	0.00	0.00	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.30	0.00	0.35
Multilane exit ramps per mile	0.00	0.00	0.00	0.35
Optional/shared exit lanes per mile	0.00	0.00	0.72	0.35
Exit only lanes per mile	0.58	0.30	0.00	0.35
Score	210	145	280	280
Overall score	228.75

Information for site MD-1 is as follows:

• Site: MD-1.
• Location: Baltimore, MD.
• Primary route: I-95.
• Secondary/intersecting route: I-695.

 

©2010 Google Earth^®
Figure 94. Photo. Aerial view of site MD-1. ⁽⁶⁴⁾

Table 63. Characteristics of MD-1.

Variable	NB	SB	EB	WB
Study length (ft)	13,450	6,520	7,770	7,755
Number of concurrent routes	1	1	1	1
Number of levels	2	2	2	2
Number of missing movements	0	0	0	0
Number of ramps	3	3	2	3
Exit ramps per mile	0.79	1.62	0.68	1.36
Entrance ramps per mile	0.39	0.81	0.68	0.68
Left exits per mile	0.39	0.81	0.00	0.00
Left entrances per mile	0.00	0.00	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.00	0.68	0.00
Multilane exit ramps per mile	0.00	0.00	0.68	0.00
Optional/shared exit lanes per mile	0.00	0.00	0.68	0.00
Exit only lanes per mile	0.79	1.62	1.36	1.36
Score	260	270	380	310
Overall score	305

Information for site NY-1 is as follows:

• Site: NY-1.
• Location: Port Chester, NY.
• Primary route: I-95.
• Secondary/intersecting route: I-287.

©2010 Google Earth^®
Figure 95. Photo. Aerial view of site NY-1. ⁽⁶⁵⁾

Table 64. Characteristics of NY-1.

Variable	NB	SB	EB	WB
Study length (ft)	15,700	15,730	14,165	9,500
Number of concurrent routes	1	1	1	1
Number of levels	2	2	2	2
Number of missing movements	0	0	0	0
Number of ramps	4	2	3	5
Exit ramps per mile	1.01	0.34	0.75	1.11
Entrance ramps per mile	0.34	0.34	0.37	1.67
Left exits per mile	0.00	0.00	0.00	0.00
Left entrances per mile	0.00	0.00	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.34	0.00	0.00
Multilane exit ramps per mile	0.00	0.00	0.00	0.00
Optional/shared exit lanes per mile	0.00	0.00	0.00	0.56
Exit only lanes per mile	1.01	0.34	0.75	0.56
Score	200	300	280	360
Overall score	285

Information for site NY-3 is as follows:

• Site: NY-3.
• Location: Poughkeepsie, NY.
• Primary routes: US-44/SR 55.
• Secondary/intersecting route: US-9.

©2011 Google Earth^®
Figure 96. Photo. Aerial view of site NY-3. ⁽⁶⁶⁾

Table 65. Characteristics of NY-3.

Variable	NB	SB	EB	WB
Study length (ft)	3,270	2,820	10,055	10,150
Number of concurrent routes	1	1	2	2
Number of levels	2	2	2	2
Number of missing movements	0	0	0	0
Number of ramps	6	6	2	2
Exit ramps per mile	3.23	5.62	0.53	0.52
Entrance ramps per mile	4.84	5.62	0.53	0.52
Left exits per mile	3.23	3.74	0.00	0.00
Left entrances per mile	3.23	3.74	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.00	0.00	0.00
Multilane exit ramps per mile	0.00	0.00	0.00	0.00
Optional/shared exit lanes per mile	1.61	1.87	0.00	0.00
Exit only lanes per mile	3.23	3.74	0.53	0.52
Score	490	470	235	195
Overall score	347.5

Information for site OH-1 is as follows:

• Site: OH-1.
• Location: Cleveland, OH.
• Primary route: I-90.
• Secondary/intersecting route: I-77.

©2010 Google Earth^®
Figure 97. Photo. Aerial view of site OH-1. ⁽⁶⁷⁾

Table 66. Characteristics of OH-1.

Variable	NB	SB	EB	WB
Study length (ft)	7,235	8,505	0	1,785
Number of concurrent routes	1	1	0	1
Number of levels	2	2	0	2
Number of missing movements	0	0	0	1
Number of ramps	5	4	0	3
Exit ramps per mile	2.92	0.62	0	8.87
Entrance ramps per mile	0.73	1.86	0	0.00
Left exits per mile	0.00	0.00	0	2.96
Left entrances per mile	0.00	0.00	0	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.00	0	5.92
Multilane exit ramps per mile	0.00	0.00	0	2.96
Optional/shared exit lanes per mile	0.73	0.62	0	5.92
Exit only lanes per mile	2.19	0.00	0	5.92
Score	480	360	-	465
Overall score	435

- Indicates no score was generated because EB approach was not present.

Information for site OH-2 is as follows:

• Site: OH-2.
• Location: Columbus, OH.
• Primary routes: I-71.
• Secondary/intersecting route: I-670.

©2010 Google Earth^®
Figure 98. Photo. Aerial view of site OH-2. ⁽⁶⁸⁾

 

Table 67. Characteristics of OH-2.

Variable	NB	SB	EB	WB
Study length (ft)	12,160	10,840	14,815	13,430
Number of concurrent routes	1	1	1	1
Number of levels	2	2	2	2
Number of missing movements	0	0	0	0
Number of ramps	8	9	8	6
Exit ramps per mile	1.30	1.95	1.43	1.18
Entrance ramps per mile	2.17	0.97	1.43	1.18
Left exits per mile	0.43	0.49	0.71	0.39
Left entrances per mile	0.43	0.00	0.36	0.39
Number of exit ramps with multiple destinations per mile	0.00	0.49	0.36	0.39
Multilane exit ramps per mile	0.43	0.49	0.71	0.79
Optional/shared exit lanes per mile	0.87	0.97	0.36	0.79
Exit only lanes per mile	0.87	1.95	1.78	1.18
Score	700	520	680	610
Overall score	627.5

Information for site OH-3 is as follows:

• Site: OH-3.
• Location: Cincinnati, OH.
• Primary route: I-71.
• Secondary/intersecting routes: I-75/US-52.

©2010 Google Earth^®
Figure 99. Photo. Aerial view of site OH-3.⁽⁶⁹⁾

Table 68. Characteristics of OH-3.

Variable	NB	SB	EB	WB
Study length (ft)	8,410	7,945	6,485	8,530
Number of concurrent routes	1.5	1.25	1	1.6
Number of levels	3	3	3	3
Number of missing movements	0	1	1	0
Number of ramps	4	4	4	5
Exit ramps per mile	1.88	1.33	1.63	1.24
Entrance ramps per mile	0.63	1.33	1.63	1.86
Left exits per mile	0.00	0.66	0.00	0.62
Left entrances per mile	0.00	1.33	1.63	0.00
Number of exit ramps with multiple destinations per mile	0.63	0.66	0.81	0.62
Multilane exit ramps per mile	0.63	1.33	0.81	0.62
Optional/shared exit lanes per mile	1.26	0.66	0.00	0.00
Exit only lanes per mile	1.26	1.99	2.44	1.86
Score	565	730	625	495
Overall score	603.75

Information for site OR-1 is as follows:

• Site: OR-1.
• Location: Portland, OR.
• Primary route: I-5.
• Secondary/intersecting routes: I-405/US-30/Fremont Bridge.

 

©2011 Google Earth^®
Figure 100. Photo. Aerial view of site OR-1. ⁽⁷⁰⁾

 

Table 69. Characteristics of OR-1.

Variable	NB	SB	EB	WB
Study length (ft)	6,220	6,580	8,340	5,760
Number of concurrent routes	1	1	1.25	1.5
Number of levels	4	4	4	4
Number of missing movements	0	0	0	0
Number of ramps	3	3	4	4
Exit ramps per mile	1.70	0.80	1.90	0.92
Entrance ramps per mile	0.85	1.60	0.63	2.75
Left exits per mile	0.00	0.00	1.27	0.00
Left entrances per mile	0.00	0.00	0.63	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.80	0.63	0.00
Multilane exit ramps per mile	0.85	0.80	0.63	0.92
Optional/shared exit lanes per mile	1.70	0.00	1.27	0.92
Exit only lanes per mile	0.85	1.60	1.27	0.92
Score	380	370	465	415
Overall score	407.5

Information for site OR-2 is as follows:

• Site: OR-2.
• Location: Portland, OR.
• Primary routes: I-5 and US-30.
• Secondary/intersecting routes: I-84/US-30.

©2011 Google Earth^®
Figure 101. Photo. Aerial view of site OR-2.⁽⁷¹⁾

 

Table 70. Characteristics of OR-2.

Variable	NB	SB	EB	WB
Study length (ft)	1,275	9,715	0	5,885
Number of concurrent routes	1.333	1.333	0	2
Number of levels	3	3	0	3
Number of missing movements	0	0	0	0
Number of ramps	3	3	0	1
Exit ramps per mile	0.00	1.09	0	0.90
Entrance ramps per mile	4.14	0.54	0	0.00
Left exits per mile	0.00	0.00	0	0.00
Left entrances per mile	0.00	0.00	0	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.54	0	0.00
Multilane exit ramps per mile	4.14	0.00	0	0.90
Optional/shared exit lanes per mile	4.14	0.54	0	0.90
Exit only lanes per mile	4.14	0.54	0	0.90
Score	395	325	-	295
Overall score	338.33

- Indicates no score was generated because the EB approach was not present.

Information for site SC-1 is as follows:

• Site: SC-1.
• Location: Columbia, SC.
• Primary routes: I-26/US-76.
• Secondary/intersecting routes: I-126, US-76, and Bush River Road.

©2010 Google Earth^®
Figure 102. Photo. Aerial view of site SC-1. ⁽⁷²⁾

 

Table 71. Characteristics of SC-1.

Variable	NB	SB	EB	WB
Study length (ft)	7,355	8,930	10,115	4,750
Number of concurrent routes	2	2	1	1
Number of levels	2	2	2	2
Number of missing movements	0	0	0	0
Number of ramps	4	3	1	1
Exit ramps per mile	1.44	1.18	0.52	0.00
Entrance ramps per mile	1.44	0.59	0.00	1.11
Left exits per mile	0.00	0.00	0.00	0.00
Left entrances per mile	0.00	0.00	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.00	0.52	0.00
Multilane exit ramps per mile	0.00	0.59	0.52	0.00
Optional/shared exit lanes per mile	0.00	0.59	0.00	0.00
Exit only lanes per mile	1.44	1.18	1.04	0.00
Score	345	315	240	50
Overall score	237.5

Information for site SC-2 is as follows:

• Site: SC-2.
• Location: Mauldin, SC.
• Primary routes: I-185 and I-385.
• Secondary/intersecting routes: I-385 and US-276.

©2011 Google Earth^®
Figure 103. Photo. Aerial view of site SC-2.⁽⁷³⁾

 

Table 72. Characteristics of SC-2.

Variable	NB	SB	EB	WB
Study length (ft)	22,720	16,200	16,055	14,460
Number of concurrent routes	1	1	1	1
Number of levels	3	3	3	3
Number of missing movements	1	1	0	0
Number of ramps	4	3	3	4
Exit ramps per mile	0.70	0.65	0.33	0.73
Entrance ramps per mile	0.23	0.33	0.66	0.73
Left exits per mile	0.00	0.00	0.00	0.00
Left entrances per mile	0.00	0.00	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.65	0.33	0.37
Multilane exit ramps per mile	0.00	0.00	0.00	0.37
Optional/shared exit lanes per mile	0.46	0.33	0.00	0.37
Exit only lanes per mile	0.23	0.33	0.33	0.73
Score	260	255	200	370
Overall score	271.25

Information for site SC-3 is as follows:

• Site: SC-3.
• Location: Rock Hill, SC.
• Primary route: I-77.
• Secondary/intersecting route: US-21.

©2010 Google Earth^®
Figure 104. Photo. Aerial view of site SC-3.⁽⁷⁴⁾

 

Table 73. Characteristics of SC-3.

Variable	NB	SB	EB	WB
Study length (ft)	20,390	19,460	0	0
Number of concurrent routes	1	1	0	0
Number of levels	2	2	0	0
Number of missing movements	0	0	0	0
Number of ramps	2	2	0	0
Exit ramps per mile	0.26	0.27	0	0
Entrance ramps per mile	0.26	0.27	0	0
Left exits per mile	0.00	0.00	0	0
Left entrances per mile	0.00	0.00	0	0
Number of exit ramps with multiple destinations per mile	0.26	0.27	0	0
Multilane exit ramps per mile	0.00	0.27	0	0
Optional/shared exit lanes per mile	0.26	0.27	0	0
Exit only lanes per mile	0.00	0.27	0	0
Score	115	270	-	-
Overall score	192.5

- Indicates no score was generated because EB and WB approaches were not present.

Information for site VA-1 is as follows:

• Site: VA-1.
• Location: Springfield, VA.
• Primary routes: I-95/I-395 Connector.
• Secondary/intersecting route(s): I-495.

©2010 Google Earth^®
Figure 105. Photo. Aerial view of site VA-1. ⁽⁷⁵⁾

 

Table 74. Characteristics of VA-1.

Variable	NB	SB	EB	WB
Study length (ft)	8,850	11,130	22,230	21,005
Number of concurrent routes	1	1	1.5	1.25
Number of levels	4	4	4	4
Number of missing movements	0	0	0	0
Number of ramps	3	4	4	4
Exit ramps per mile	0.60	0.95	0.48	0.75
Entrance ramps per mile	1.19	0.95	0.48	0.25
Left exits per mile	0.00	0.00	0.00	0.25
Left entrances per mile	0.00	0.47	0.24	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.95	0.24	0.25
Multilane exit ramps per mile	0.60	0.95	0.48	0.25
Optional/shared exit lanes per mile	0.00	0.95	0.24	0.00
Exit only lanes per mile	1.19	1.42	0.95	1.01
Score	340	470	330	325
Overall score	366.25

Information for site VA-2 is as follows:

• Site: VA-2.
• Location: Washington, DC.
• Primary route: I-395.
• Secondary/intersecting route: SR 27.

©2010 Google Earth^®
Figure 106. Photo. Aerial view of site VA-2. ⁽⁷⁶⁾

Table 75. Characteristics of VA-2.

Variable	NB	SB	EB	WB
Study length (ft)	11,920	11,560	11,070	8,420
Number of concurrent routes	1	1	1	1.2
Number of levels	2	2	2	2
Number of missing movements	0	1	0	1
Number of ramps	6	5	10	12
Exit ramps per mile	1.77	0.46	1.91	2.51
Entrance ramps per mile	0.89	1.83	2.86	1.88
Left exits per mile	0.44	0.00	0.00	1.25
Left entrances per mile	0.00	0.46	0.48	0.00
Number of exit ramps with multiple destinations per mile	0.44	0.46	1.43	0.63
Multilane exit ramps per mile	0.00	0.00	0.95	0.63
Optional/shared exit lanes per mile	0.00	0.00	0.95	0.63
Exit only lanes per mile	1.77	0.46	1.91	3.14
Score	460	385	750	790
Overall score	596.25

Information for site VA-3 is as follows:

• Site: VA-3.
• Location: Norfolk, VA.
• Primary routes: I-664.
• Secondary/intersecting routes: I-64, I-264, US-13, US-58, US-460, and SR 191.

©2010 Google Earth^®
Figure 107. Photo. Aerial view of site VA-3.⁽⁷⁷⁾

 

Table 76. Characteristics of VA-3.

Variable	NB	SB	EB	WB
Study length (ft)	23,105	19,080	8,165	10,960
Number of concurrent routes	1	1.143	2	1
Number of levels	2	2	2	2
Number of missing movements	0	0	0	0
Number of ramps	5	7	4	2
Exit ramps per mile	0.46	1.11	1.29	0.48
Entrance ramps per mile	0.69	0.55	1.29	0.48
Left exits per mile	0.00	0.00	0.00	0.48
Left entrances per mile	0.23	0.00	0.00	0.00
Number of exit ramps with multiple destinations per mile	0.00	0.00	0.00	0.00
Multilane exit ramps per mile	0.23	0.28	0.65	0.00
Optional/shared exit lanes per mile	0.00	0.00	0.00	0.00
Exit only lanes per mile	0.91	1.38	1.94	0.48
Score	330	415	345	210
Overall score	325

 

ACKNOWLEDGMENTS

The research reported herein was performed for FHWA by TTI. The authors wish to acknowledge the individuals who contributed to this research by participating in the simulation surveys, assisting with field study site selection, and serving as technical experts by providing feedback on which characteristics should be included in the spreadsheet tool.

The authors also wish to acknowledge those within TTI who assisted with the literature review and helped with data collection and reduction for either the simulator study or the decision tool. Those individuals include the following:

• Brooke Ullman.
• Christopher White.
• Hailey Minter.
• Laura Higgins.
• Christine Yager.
• Katie Connell.

REFERENCES

1. Federal Highway Administration. (2009). Manual on Uniform Traffic Control Devices. Federal Highway Administration, Washington, DC.



2. AASHTO. (2011). A Policy on Geometric Design of Highways and Streets, American Association of State Highway and Transportation Officials, Washington, DC.


3. Upchurch, J., Fisher, D., and Waraich, B. (2005). “Guide Signing of Two-Lane Exits with an Option Lane: Evaluation of Human Factors,” Transportation Research Record 1918,35–45, Transportation Research Board, Washington, DC.


4. Upchurch, J., Fisher, D., and Waraich, B. (2003). Signing of Two-Lane Exits with an Option Lane, NCHRP Project 20-7 (15S) Final Report, Transportation Research Board, Washington, DC.


5. Golembiewski, G., Katz, B., Dagnall, E., and Bertola, M.A. (2011). Evaluation of Combined Lane Use and Destination Sign Alternatives for Overhead-Mounted Guide Signs on Multilane Conventional Road Intersection Approaches. Traffic Control Devices Pooled Fund Study, TPF-5(065), Science Applications International Corporation, Washington, DC.


6. Fitzpatrick, K., Lienau, T.K., Ogden, M.A., Lance, M.T., and Urbanik, T. (1993). Freeway Exit Lane Drops in Texas, Research Report 0-1292-1F, Texas Transportation Institute, College Station, TX.


7. Chrysler, S.T., Williams, A., Funkhouser, D.S., Holick, A.J., and Brewer, M.A. (2007). Driver Comprehension of Diagrammatic Freeway Guide Signs, Research Report 5147-1, Texas Transportation Institute, College Station, TX.


8. Somers, R.A., Hawkins, H.G., Jasek, D.L., and Urbanik, T. (1996). Evaluation of Guide Signing at Right Multilane Freeway Exits with Optional Lanes,Research Report 0-1467-5, Texas Transportation Institute, College Station, TX.


9. Ullman, B.R., Finley, M.D., Chrysler, S.T., Trout, N.D., Nelson, A.A., and Young, S. (2010). Guidelines for the Use of Pavement Marking Symbols at Freeway Interchanges: Final Report, Report No. FHWA/TX-10/05890-1, Texas Transportation Institute, College Station, TX. Obtained from: http://tti.tamu.edu/documents/0-5890-1.pdf Site last accessed June 11, 2013.


10. Doctor, M., Merritt, G., and Moler, S. (2009). “Designing Complex Interchanges,” Public Roads, 73(3), 3–11.


11. Krause, R. and Shelley, M.C. (1990). Positive Guidance: New Visions for Safer Highways,National Advisory Task Force on Positive Guidance, Council of State Governments, Lexington, KY.


12. Allen, T.M., Lunenfeld, H., and Alexander, G.F. (1971). “Driver Information Needs,” Transportation Research Record 366, Transportation Research Board, Washington, DC.


13. Fontaine. M.D., Chrysler, S.T., and Ford, G.L. (2002). Freeway Guide Signing: Review of Past Literature, Report No. FHWA/TX-02/0-4170-1, Texas Transportation Institute, College Station TX. Obtained from: http://tti.tamu.edu/documents/0-4170-1.pdf. Site last accessed June 11, 2013.


14. Mitchell, A. and Forbes, T.W. (1942). “Design of Sign Letter Sizes,” Proceedings of the American Society of Civil Engineers, Washington, DC.


15. Bhise, V.V. and Rockwell, T.H. (1973). “Toward the Development of a Methodology for Evaluating Highway Signs Based on Driver Information Acquisition,” Transportation Research Record 440, Transportation Research Board, Washington, DC.


16. Agg, H.J. (1994). Direction Sign Overload, Project Report 77, Transportation Research Laboratory, U.S. Department of Transportation, Washington, DC.


17. Hall, R.D., McDonald, M., and Rutley, K.S. (1989). An Experiment to Assess the Reading Times of Direction Signs, 333–350, Vision in Vehicles 3rd Conference, Aachen, Germany.


18. McNees, R.W. and Messer, C.J. (1982). Reading Time and Accuracy of Response to Simulated Urban Freeway Guide Signs,Texas Transportation Institute, College Station, TX.


19. Forbes, T.W. and Holmes, R.S. (1939). “Legibility Distances of Highway Destination Signs in Relation to Letter Height,” Highway Research Board Proceedings, Highway Research Board, Washington, DC.


20. Allen, T.M. (1958). “Night Legibility Distance of Highway Signs,” Highway Research Bulletin 191, Washington, DC.


21. Kelly, A.B. (1997). Perceptual and Cognitive Factors in Legend Legibility for Large Freeway Guide Signs, Master of Science Thesis, Texas A&M University, College Station, TX.


22. Carlson, P.J. (2001). Evaluation of Clearview Alphabet with Microprismatic Reflective Sheetings, Report No. FHWA/TX-02/4049-1, Texas Transportation Institute, College Station, TX.


23. Garvey, P.M., Pietrucha, M.T., and Meeker, D. (1997). “Effects of Font and Capitalization on Legibility of Guide Signs,” Transportation Research Record 1605, 73–79, Transportation Research Board, Washington, DC.


24. Gordon, D.A. (1982). “Legibility of Highway Guide Signs,” Transportation Research Record 855, 1–6, Transportation Research Board, Washington, DC.


25. Messer, C.J. and McNees, R.W. (1981). Evaluating Urban Freeway Guide Signing—Executive Summary and Level of Service,Report 220-4F, Texas Transportation Institute, College Station, TX.


26. Lerner, N.D., Llaneras, R.E., McGee, H.W., Taori, S., and Alexander, G. (2003). Additional Investigations into Driver Information Overload, NCHRP Report No. 488, Transportation Research Board, Washington, DC.


27. Leisch, J.P. (2003). Freeway and Interchange Geometric Design Handbook, Institute of Transportation Engineers, Washington, DC.


28. United Kingdom Department for Transport. (2003). Traffic Signs Manual. Obtained from: http://www.dft.gov.uk/stellent/groups/dft_control/documents/contentservertemplate/dft_index.hcst?n=14633&l=2. Site last accessed February 2006.


29. Strassenverkehrs-Ordnung or German Road Traffic Regulations, Part II, Section 42.8. Obtained from: http://www.fahrschule.de/Verkehrsrecht/StVO/. Site last accessed February 2006.


30. Eberhard, J.W. and Berger, W.G. (1972). “Criteria for the Design and Deployment of Advanced Graphic Guide Signs,” Highway Research Record 414, Transportation Research Board, Washington, DC.


31. Gordon, D.A. (1972). “Evaluation of Diagrammatic Guide Signs,” Highway Research Record 414, Transportation Research Board, Washington, DC.


32. Zajkowski, M.M. and Nees, M. (1976). “Diagrammatic Highway Signs: The Laboratory Revisited,” Transportation Research Record 600, 7–13, Transportation Research Board, Washington, DC.


33. Staplin, L., Lococo, K., Byington, S., and Harkey, D. (2001). Guidelines and Recommendations to Accommodate Older Drivers and Pedestrians, Report No. FHWA-RD-01-051, Federal Highway Administration, Washington, DC.


34. Skowronek, D.A. (1990). An Investigation of Potential Urban Freeway Guide Sign Problem Locations in Houston, Texas,Master of Science Thesis, Texas A&M University, College Station, TX.


35. McGuiness, R.A. (1983). “Driver Opinions on Freeway Signing and Construction Strategies,” ITE Journal, 53(7), 12–14, Institute of Transportation Engineers, Washington, DC.


36. Roberts, A.M. and Klipple, A.G. (1976). “Driver Expectancies at Freeway Lane Drops,” Transportation Research Record 600, 42–44, Transportation Research Board, Washington, DC.


37. Hanscom, F.R. (1972). “Evaluation of Diagrammatic Signing at Capital Beltway Exit 1,” Highway Research Record 414, 50–58, Highway Research Board, Washington, DC.


38. Mast, T.M. and Kolsrud, G.S. (1972). Diagrammatic Guide Signs for Use on Controlled Access Highways, Volume 1, Recommendations for Diagrammatic Guide Signs, Report No. DOT-FH-11-7815, Federal Highway Administration, Washington, DC.


39. Ho, G., Scialfa, C.T., Caird, J.K., and Graw, T. (2001). “Visual Search for Traffic Signs: The Effects of Clutter, Luminance, and Aging,” Human Factors Journal, 43(2), 194–207.


40. Salvucci, D.D. and Liu, A. (2002). “The Time Course of a Lane Change Driver Control and Eye-Movement Behavior,” Transportation Research Journal Part F: Traffic Psychology and Behavior, 5(2), 123–132.


41. Lunenfeld, H. and Alexander, G.J. (1976). “Signing Treatments for Interchange Lane Drops,” Transportation Research Record 600, 1–6, Transportation Research Board, Washington, DC.


42. U.S. Department of Transportation. (2009). Highway Statistics 2009, Federal Highway Administration, Washington, DC. Obtained from: https://www.fhwa.dot.gov/policyinformation/statistics/2009/dl22.cfm. Site last accessed June 11, 2013.


43. U.S. Census Bureau. (2009). American Community Survey 2009. Obtained from: http://factfinder.census.gov/servlet/STTable?_bm=y&-context=st&-qr_name=ACS_2009_5YR_G00_S1501&-ds_name=ACS_2009_5YR_G00_&-tree_id=5309&-redoLog=false&-_caller=geoselect&-geo_id=04000US48&-format=&-_lang=en. Site last accessed September 1, 2011.


44. AASHTO. (2001). Guidelines for the Selection of Supplemental Guide Signs for Traffic Generators Adjacent to Freeways, American Association of State Highway and Transportation Officials, Washington, DC.


45. Google Earth^®. (2011). Example of missing movements. Data date: May 5, 2010. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: July 27, 2011.


46. Google Earth^®(2011). Configuration of site OH-2. Data date: May 28, 2010. Generated by: Texas A&M Transportation Institute . Obtained from: Google Earth^®. Last accessed: October 28, 2011.


47. Google Earth^®. (2011). Configuration of site SC-3. Data date: April 10, 2010.Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: July 21, 2011.


48. Federal Highway Administration. (2004). Standard Highway Sign Manual, Federal Highway Administration, Washington, DC.


49. Google Earth^®. (2011). Configuration of site SC-2. Data date: February 8, 2011. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 21, 2011.


50. Google Earth^®. (2011). Aerial view of site AZ-1. Data date: March 3, 2011. Generated by: Texas A&M Transportation Institute . Obtained from: Google Earth^®. Last accessed: July 29, 2011.


51. Google Earth^® (2011). Aerial view of site AZ-2. Data date: March 3, 2011. Generated by: Texas A&M Transportation Institute . Obtained from: Google Earth^®. Last accessed: October 24, 2011.


52. Google Earth^®. (2011). Aerial view of site AZ-3. Data date: May 14, 2011. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: July 29, 2011.


53. Google Earth^®. (2011). Aerial view of site DE-1. Data date: October 7, 2011. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 7, 2011.


54. Google Earth^®. (2011). Aerial view of site DE-2. Data date: October 7, 2011. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 7, 2011.


55. Google Earth^®. (2011). Aerial view of site DE-3. Data date: October 7, 2011. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 7, 2011.


56. Google Earth^®. (2011). Aerial view of site GA-2. Data date: October 16, 2011. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 16, 2011.


57. Google Earth^®. (2011). Aerial view of site GA-3. Data date: October 16, 2011. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 16, 2011.


58. Google Earth^®. (2011). Aerial view of site GA-4. Data date: October 6, 2011. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: July 28, 2011.


59. Google Earth^®. (2011). Aerial view of site IN-1. Data date: June 30, 2010. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: July 27, 2011.


60. Google Earth^®. (2011). Aerial view of site IN-3. Data date: May 5, 2010. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: July 27, 2011.


61. Google Earth^®. (2011). Aerial view of site IA-1. Data date: June 5, 2011. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: July 27, 2011.


62. Google Earth^®. (2011). Aerial view of site IA-2. Data date: October 3, 2010. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 21, 2011.


63. Google Earth^®. (2011). Aerial view of site IA-3. Data date: June 6, 2011. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: July 27, 2011.


64. Google Earth^®. (2011). Aerial view of site MD-1. Data date: August 29, 2010. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 24, 2011.


65. Google Earth^®. (2011). Aerial view of site NY-1. Data date: June 17, 2010. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: July 25, 2011.


66. Google Earth^®. (2011). Aerial view of site NY-3. Data date: October 7, 2011. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 7, 2011.


67. Google Earth^®. (2011). Aerial view of site OH-1. Data date: May 29, 2010. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 31, 2011.


68. Google Earth^®. (2011). Aerial view of site OH-2. Data date: May 28, 2010. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 28, 2011.


69. Google Earth^®. (2011). Aerial view of site OH-3. Data date: July 1, 2010. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 24, 2011.


70. Google Earth^®. (2011). Aerial view of site OR-1. Data date: August 20, 2011. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 31, 2011.


71. Google Earth^®. (2011). Aerial view of site OR-2. Data date: August 20, 2011. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 31, 2011.


72. Google Earth^®. (2011). Aerial view of site SC-1. Data date: October 1, 2010. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: July 28, 2011.


73. Google Earth^®. (2011). Aerial view of site SC-2. Data date: February 8, 2011. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 21, 2011.


74. Google Earth^®. (2011). Aerial view of site SC-3. Data date: April 10, 2010. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: July 21, 2011.


75. Google Earth^®. (2011). Aerial view of site VA-1. Data date: August 28, 2010. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: July 25, 2011.


76. Google Earth^®. (2011). Aerial view of site VA-2. Data date: August 28, 2010. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 24, 2011.


77. Google Earth^®. (2011). Aerial view of site VA-3. Data date: April 6, 2010. Generated by: Texas A&M Transportation Institute. Obtained from: Google Earth^®. Last accessed: October 17, 2011.