Cal. Veh. Code § 35551.5

(a) The provisions of this section shall apply only to combinations of vehicles which contain a trailer or semitrailer. Each vehicle in such combination of vehicles, and every such combination of vehicles, shall comply with either Section 35551 or with subdivisions (b), (c), and (d) of this section.
(b) The gross weight imposed upon the highway by the wheels on any one axle of a vehicle shall not exceed 18,000 pounds and the gross weight upon any one wheel, or wheels, supporting one end of an axle and resting upon the roadway, shall not exceed 9,500 pounds, except that the gross weight imposed upon the highway by the wheels on any front steering axle of a motor vehicle shall not exceed 12,500 pounds. The gross weight limit provided for weight bearing upon any one wheel, or wheels, supporting one end of an axle shall not apply to vehicles the loads of which consist of livestock. The following vehicles are exempt from the front axle weight limits specified in this subdivision:
1. (1) Trucks transporting vehicles.
2. (2) Trucks transporting livestock.
3. (3) Dump trucks.
4. (4) Cranes.
5. (5) Buses.
6. (6) Transit mix concrete or cement trucks, and trucks that mix concrete or cement at, or adjacent to, a jobsite.
7. (7) Motor vehicles that are not commercial vehicles.
8. (8) Vehicles operated by any public utility furnishing electricity, gas, water, or telephone service.
9. (9) Trucks or truck tractors with a front axle at least four feet to the rear of the foremost part of the truck or truck tractor, not including the front bumper.
10. (10) Trucks transporting garbage, rubbish, or refuse.
11. (11) Trucks equipped with a fifth wheel when towing a semitrailer.
12. (12) Tank trucks which have a cargo capacity of at least 1,500 gallons.
13. (13) Trucks transporting bulk grains or bulk livestock feed.

(c) The total gross weight with load imposed on the highway by any group of two or more consecutive axles of a vehicle in such combination of vehicles or of such combination of vehicles where the distance between the first and last axles of the two or more consecutive axles is 18 feet or less shall not exceed that given for the respective distance in the following table:

Distance in feet	Allowed load in
between first and	pounds on group
last axles of group	of axles
4	32,000
5	32,000
6	32,200
7	32,900
8	33,600
9	34,300
10	35,000
11	35,700
12	36,400
13	37,100
14	43,200
15	44,000
16	44,800
17	45,600
18	46,400

(d) The total gross weight with load imposed on the highway by any vehicle in such combination of vehicles or of such combination of vehicles where the distance between the first and last axles is more than 18 feet shall not exceed that given for the respective distances in the following table:

Distance	Allowed load
in feet	in pounds
19	47,200
20	48,000
21	48,800
22	49,600
23	50,400
24	51,200
25	55,250
26	56,100
27	56,950
28	57,800
29	58,650
30	59,500
31	60,350
32	61,200
33	62,050
34	62,900
35	63,750
36	64,600
37	65,450
38	66,300
39	68,000
40	70,000
41	72,000
42	73,280
43	73,280
44	73,280
45	73,280
46	73,280
47	73,280
48	73,280
49	73,280
50	73,280
51	73,280
52	73,600
53	74,400
54	75,200
55	76,000
56 or over	76,800

(e) The distance between axles shall be measured to the nearest whole foot. When a fraction is exactly six inches, the next larger whole foot shall be used.
(f) The gross weight limits expressed by this section shall include all enforcement tolerances.
(g) Nothing in this section shall affect the right to prohibit the use of any highway or any bridge or other structure thereon in the manner and to the extent specified in Article 4 (commencing with Section 35700) and Article 5 (commencing with Section 35750) of Chapter 5 of Division 15.
(h) The Legislature, in enacting this section, does not intend to increase, and this section shall not be construed to allow, statutory weights any greater than existed prior to January 1, 1976.