Federal & State Regulations | Size/Weight limits - Washington

Dimension	National Network	State and Other Supplemental Highways
Width:	8' 6"	8' 6"
Height:	14'	14'
Length:	National Network	On All Other
Bus	46'	46'
Articulated bus	61'	61'
Straight Trucks	40'	40'
Straight truck and trailer	75'	75'
Tractor-semitrailer combinations	No limit with legal trailer	No limit with legal trailer
Semitrailer	53'	53'
Tractor-twin-trailer combination	No limit with legal trailer limit	No limit with legal trailer limit
Trailers of twin-trailer combinations	61' measured from front of 1st trailing unit or load to rear of 2nd trailing unit or load	61' measured from front of 1st trailing unit or load to rear of 2nd trailing unit or load
Boat-transporter combination	65'	65'
Overhang limitations	3' front, 4' rear	3' front, 4' rear
Stinger-steered boat-transporter	75'	75'
Overhang limitations	3' front, 4' rear	3' front, 4' rear
Auto-transporter	65'	65'
Overhang limitations	3' front, 4' rear	3' front, 4' rear
Stinger-steered auto-transporter	80'	80'
Overhang limitations	4' front, 6' rear	4' front, 6' rear
Saddlemount	97' up to 3	97' up to 3
General overhang limitations	3' front, 15' rear from center of the last axle	3' front, 15' rear from center of the last axle
Drawbar	15'	15'
Dromedary
Kingpin to rearaxle
Length special limitations or restrictions
Weight:	Interstate and Defense Highways	On All Other
Steer axle	600 lb/in	600 lb/in
Single axle	20,000	20,000
Tandem axle	34,000	34,000
Tridem axle
Gross vehicle weight	105,500 max. determined by number of axles, spacings, and tire size	105,500 max. determined by number of axles, spacings, and tire size
Load per inch width of tire	500 on vehicles with axles equipped with single tires	500 on vehicles with axles equipped with single tires
Per wheel
Tolerances
APU allowance	550	550
Natural gas allowance	2,000
Weight special limitations or restrictions

Bridge rules

THE FEDERAL BRIDGE FORMULA IS UTILIZED TO DETERMINE THE MAXIMUM GROSS VEHICLE WEIGHTS AND MAXIMUM WEIGHTS OF AXLE GROUPS ALLOWED ON WASHINGTON HIGHWAYS.

Washington will allow legal vehicle weights of up to 105,500 pounds, single axle weights of up to 20,000 pounds, and tandem axle weights of up to 34,000 pounds, as long as the vehicle carrying such weights falls within the axle spacing restrictions of the federal bridge formula.

W = the maximum weight in pounds that can be carried on a group of two or more axles to the nearest 500 lb ;

L = spacing in feet between the outer axles of any two or more consecutive axles (distance measured from centers of axles); and

N = number of axles being considered.

Vehicle weight table (RCW 46.44.041)
Feet	2 Axle	3 Axle	4 Axle	5 Axle	6 Axle	7 Axle	8 Axle	9 Axle
When inches are involved; under six inches take the lower, 6 inches or over, the higher, except between 8 and 9 feet.
4	34,000				*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 20,000 lb, 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 34,000 lb each, if the overall distance between the first and last axles of such consecutive sets of tandem axles is 36 ft or more.
5	34,000
6	34,000
7	34,000
8 & Less	34,000	34,000
over 8	38,000	42,000
9	39,000	42,500
10	40,000	43,500
11		44,000
12		45,000	50,000
13		45,500	50,500
14		46,500	51,500
15		47,000	52,000
16		48,000	52,500	58,000
17		48,500	53,500	58,500
18		49,500	54,000	59,000
19		50,000	54,500	60,000
20		51,000	55,500	60,500	66,000
21		51,500	56,000	61,000	66,500
22		52,500	56,500	61,500	67,000
23		53,000	57,500	62,500	68,000
24		54,000	58,000	63,000	68,500	74,000
25		54,500	58,500	63,500	69,000	74,500
26		55,500	59,500	64,000	69,500	75,000
27		56,000	60,000	65,000	70,000	75,500
28		57,000	60,500	65,500	71,000	76,500	82,000
29		57,500	61,500	66,000	71,500	77,000	82,500
30		58,500	62,000	66,500	72,000	77,500	83,000
31		59,000	62,500	67,500	72,500	78,000	83,500
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	105,000
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

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['Size and Weight Limits']

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Size/Weight limits - Washington

Bridge rules