Bureau of Transportation Statistics (BTS)
Printable Version

Table 4 - Percentile and Pace Speed Characteristics

Excel | CSV

Six-lane freeway sections

Site (highway) Direction Lane 15th percentile speed (u15) 85th percentile speed (u85) 10 mph pace Vehicles in pace (%)
320 (I-75) NB Shoulder 64 76 66 - 76 66
Middle 69 79 70 - 80 76
Median 75 83 74 - 84 76
SB Shoulder 63 75 66 - 76 66
Middle 70 80 71 - 81 78
Median 76 86 76 - 86 70
9904 (I-75) NB Shoulder 62 73 65 - 75 68
Middle 69 77 67 - 77 77
Median 73 80 71 - 81 76
SB Shoulder 64 74 65 - 75 77
Middle 71 79 68 - 78 75
Median 74 82 70 - 80 70
9905 (I-95) NB Shoulder 63 74 63 - 73 68
Middle 68 78 68 - 78 72
Median 72 83 74 - 84 60
SB Shoulder 63 73 63 - 73 70
Middle 69 78 70 - 80 78
Median 73 81 74 - 84 72

Four-lane freeway sections

Site (highway) Direction Lane 15th percentile speed (u15) 85th percentile speed (u85) 10 mph pace Vehicles in pace (%)
9901 (I-10) WB Shoulder 67 78 69 - 79 69
Median 73 82 73 - 83 75
EB Shoulder 67 78 69 - 79 70
Median 73 82 73 - 83 72
9928 (I-10) WB Shoulder 62 73 64 - 74 66
Median 69 78 68 - 78 77
EB Shoulder 65 75 66 - 76 69
Median 68 77 67 - 77 77
351 (I-75) WB Shoulder 65 79 69 - 79 62
Median 70 84 72 - 82 59
EB Shoulder 67 81 70 - 80 57
Median 77 94 82 - 92 52
9919 (I-95) NB Shoulder 63 74 67 - 77 60
Median 60 79 72 - 82 49
SB Shoulder 62 72 64 - 74 63
Median 64 71 64 - 74 63
9932 Turnpike NB Shoulder 64 76 65 - 75 66
Median 72 81 72 - 82 70
SB Shoulder 65 77 68 - 78 60
Median 73 84 73 - 83 70

Key: EB = eastbound; NB = northbound; SB = southbound; WB = westbound.