PDFRCW 46.44.041

Maximum gross weights—Wheelbase and axle factors.

No vehicle or combination of vehicles shall operate upon the public highways of this state with a gross load on any single axle in excess of twenty thousand pounds, or upon any group of axles in excess of that set forth in the following table, except that two consecutive sets of tandem axles may carry a gross load of thirty-four thousand pounds each, if the overall distance between the first and last axles of such consecutive sets of tandem axles is thirty-six feet or more.
The following table is based on the following formula: W = 500((LN/N-1)+12N+36). W is the maximum weight in pounds (to the nearest 500 pounds) carried on any group of two (2) or more consecutive axles. L is the distance in feet between the extremes of any group of two (2) or more consecutive axles. N is the number of axles under consideration.
Distance in feet between the extremes of any group of 2 or more consecutive axles
 
Maximum load in pounds carried on any group of 2 or more consecutive axles
 
2
3
4
5
 
6
 
7
 
8
 
9
axles
axles
axles
axles
 
axles
 
axles
 
axles
 
axles
 
 
 
 
 
 
 
 
 
 
4
34,000
 
 
 
 
 
 
 
 
5
34,000
 
 
 
 
 
 
 
 
6
34,000
 
 
 
 
 
 
 
 
7
34,000
 
 
 
 
 
 
 
 
8 & less
34,000
34,000
 
 
 
 
 
 
 
more than 8
38,000
42,000
 
 
 
 
 
 
 
9
39,000
42,500
 
 
 
 
 
 
 
10
40,000
43,500
 
 
 
 
 
 
 
11
 
44,000
49,000
 
 
 
 
 
 
12
 
45,000
50,000
 
 
 
 
 
 
13
 
45,500
50,500
 
 
 
 
 
 
14
 
46,500
51,500
56,500
 
 
 
 
 
15
 
47,000
52,000
57,000
 
 
 
 
 
16
 
48,000
52,500
58,000
 
 
 
 
 
17
 
48,500
53,500
58,500
 
 
 
 
 
18
 
49,500
54,000
59,000
64,500
 
 
 
 
19
 
50,000
54,500
60,000
65,000
 
 
 
 
20
 
51,000
55,500
60,500
66,000
 
 
 
 
21
 
51,500
56,000
61,000
66,500
72,000
 
 
 
22
 
52,500
56,500
61,500
67,000
72,500
 
 
 
23
 
53,000
57,500
62,500
68,000
73,000
 
 
 
24
 
54,000
58,000
63,000
68,500
74,000
 
 
 
25
 
54,500
58,500
63,500
69,000
74,500
80,000
 
 
26
 
55,500
59,500
64,000
69,500
75,000
80,500
 
 
27
 
56,000
60,000
65,000
70,000
75,500
81,000
 
 
28
 
57,000
60,500
65,500
71,000
76,500
82,000
87,500
 
29
 
57,500
61,500
66,000
71,500
77,000
82,500
88,000
 
30
 
58,500
62,000
66,500
72,000
77,500
83,000
88,500
 
31
 
59,000
62,500
67,500
72,500
78,000
83,500
89,000
 
32
 
60,000
63,500
68,000
73,000
78,500
84,500
90,000
 
33
 
 
64,000
68,500
74,000
79,000
85,000
90,500
 
34
 
 
64,500
69,000
74,500
80,000
85,500
91,000
 
35
 
 
65,500
70,000
75,000
80,500
86,000
91,500
 
36
 
 
66,000
70,500
75,500
81,000
86,500
92,000
 
37
 
 
66,500
71,000
76,000
81,500
87,000
93,000
 
38
 
 
67,500
71,500
77,000
82,000
87,500
93,500
 
39
 
 
68,000
72,500
77,500
82,500
88,500
94,000
 
40
 
 
68,500
73,000
78,000
83,500
89,000
94,500
 
41
 
 
69,500
73,500
78,500
84,000
89,500
95,000
 
42
 
 
70,000
74,000
79,000
84,500
90,000
95,500
 
43
 
 
70,500
75,000
80,000
85,000
90,500
96,000
 
44
 
 
71,500
75,500
80,500
85,500
91,000
96,500
 
45
 
 
72,000
76,000
81,000
86,000
91,500
97,500
 
46
 
 
72,500
76,500
81,500
87,000
92,500
98,000
 
47
 
 
73,500
77,500
82,000
87,500
93,000
98,500
 
48
 
 
74,000
78,000
83,000
88,000
93,500
99,000
 
49
 
 
74,500
78,500
83,500
88,500
94,000
99,500
 
50
 
 
75,500
79,000
84,000
89,000
94,500
100,000
 
51
 
 
76,000
80,000
84,500
89,500
95,000
100,500
 
52
 
 
76,500
80,500
85,000
90,500
95,500
101,000
 
53
 
 
77,500
81,000
86,000
91,000
96,500
102,000
 
54
 
 
78,000
81,500
86,500
91,500
97,000
102,500
 
55
 
 
78,500
82,500
87,000
92,000
97,500
103,000
 
56
 
 
79,500
83,000
87,500
92,500
98,000
103,500
 
57
 
 
80,000
83,500
88,000
93,000
98,500
104,000
 
58
 
 
 
84,000
89,000
94,000
99,000
104,500
 
59
 
 
 
85,000
89,500
94,500
99,500
105,500
 
60
 
 
 
85,500
90,000
95,000
100,500
105,500
 
61
 
 
 
86,000
90,500
95,500
101,000
105,500
 
62
 
 
 
86,500
91,000
96,000
101,500
105,500
 
63
 
 
 
87,500
92,000
96,500
102,000
105,500
 
64
 
 
 
88,000
92,500
97,500
102,500
105,500
 
65
 
 
 
88,500
93,000
98,000
103,000
105,500
 
66
 
 
 
89,000
93,500
98,500
103,500
105,500
 
67
 
 
 
90,000
94,000
99,000
104,500
105,500
 
68
 
 
 
90,500
95,000
99,500
105,000
105,500
 
69
 
 
 
91,000
95,500
100,000
105,500
105,500
 
70
 
 
 
91,500
96,000
101,000
105,500
105,500
 
71
 
 
 
92,500
96,500
101,500
105,500
105,500
 
72
 
 
 
93,000
97,000
102,000
105,500
105,500
 
73
 
 
 
93,500
98,000
102,500
105,500
105,500
 
74
 
 
 
94,000
98,500
103,000
105,500
105,500
 
75
 
 
 
95,000
99,000
103,500
105,500
105,500
 
76
 
 
 
95,500
99,500
104,500
105,500
105,500
 
77
 
 
 
96,000
100,000
105,000
105,500
105,500
 
78
 
 
 
96,500
101,000
105,500
105,500
105,500
 
79
 
 
 
97,500
101,500
105,500
105,500
105,500
 
80
 
 
 
98,000
102,000
105,500
105,500
105,500
 
81
 
 
 
98,500
102,500
105,500
105,500
105,500
 
82
 
 
 
99,000
103,000
105,500
105,500
105,500
 
83
 
 
 
100,000
104,000
105,500
105,500
105,500
 
84
 
 
 
 
104,500
105,500
105,500
105,500
 
85
 
 
 
 
105,000
105,500
105,500
105,500
 
86 or more
 
 
 
 
105,500
105,500
105,500
105,500
When inches are involved: Under six inches take lower, six inches or over take higher. The maximum load on any axle in any group of axles shall not exceed the single axle or tandem axle allowance as set forth in the table above.
The maximum axle and gross weights specified in this section are subject to the braking requirements set up for the service brakes upon any motor vehicle or combination of vehicles as provided by law.
Loads of not more than eighty thousand pounds which may be legally hauled in the state bordering this state which also has a sales tax, are legal in this state when moving to a port district within four miles of the bordering state except on the interstate system. This provision does not allow the operation of a vehicle combination consisting of a truck tractor and three trailers.
Notwithstanding anything contained herein, a vehicle or combination of vehicles in operation on January 4, 1975, may operate upon the public highways of this state, including the interstate system within the meaning of section 127 of Title 23, United States Code, with an overall gross weight upon a group of two consecutive sets of dual axles which was lawful in this state under the laws, regulations, and procedures in effect in this state on January 4, 1975.
[ 2016 c 24 s 1; 1997 c 198 s 1; 1995 c 171 s 1. Prior: 1993 c 246 s 1; 1993 c 102 s 3; prior: 1988 c 229 s 1; 1988 c 6 s 2; 1985 c 351 s 3; 1977 c 81 s 2; 1975-'76 2nd ex.s. c 64 s 22.]

NOTES:

Effective date of 1993 c 102 and c 123—1993 sp.s. c 23: See note following RCW 46.16A.455.
Effective dates—Severability—1975-'76 2nd ex.s. c 64: See notes following RCW 46.16A.455.