Md. Code Ann., Transp. § 24-109 – Limits for gross weight of vehicle or combination of vehicles

(a)
1. (1) In this section the following words have the meanings indicated.
2. (2) “Single axle weight” means the total weight transmitted by all wheels whose centers may be included between 2 parallel transverse vertical planes 40 inches apart extending across the full width of the vehicle.
3. (3) “Tandem axle weight” means the total weight transmitted to the road by 2 or more consecutive axles whose centers may be included between parallel vertical planes spaced more than 40 inches apart but not more than 96 inches apart extending across the full width of the vehicle.
(b) An over-the-road bus or any vehicle that is regularly and exclusively used as an intrastate public agency passenger bus:
1. (1) Is exempt from tandem axle weight limits provided in this section; but
2. (2) Shall comply with the vehicle and combination of vehicles weight limits provided in this section that are not tandem axle weight limits.
(c) Notwithstanding any other provisions of this title, the overall gross weight on a group of 2 or more consecutive axles may not exceed an amount produced by application of the following formula:
(
LN
)
W = 500
(
+
12N
+
36
)
(
N - 1
)
where “W” = overall gross weight on any group of 2 or more consecutive axles to the nearest 500 pounds, “L” = distance in feet measured horizontally between the vertical centerlines of the extreme of any group of 2 or more consecutive axles, and “N” = number of axles in group under consideration, except that 2 consecutive sets of tandem axles may carry a gross load of 34,000 pounds each providing the overall distance between the first and last axles of such consecutive sets of tandem axles is 36 feet or more; provided, that such overall gross weight may not exceed eighty thousand (80,000) pounds, including any enforcement or statutory tolerances.
(d) The following table indicates the permissible overall gross weights based upon the above formula:
Distance in feet between the extremes of any group of 2 or more consecutive axles
2 axles
3 axles
4 axles
5 axles
6 axles
7 axles
4
34,000
5
34,000
6
34,000
7
34,000
8
and 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
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
29
57,500
61,500
66,000
71,500
77,000
30
58,500
62,000
66,500
72,000
77,500
31
59,000
62,500
67,500
72,500
78,000
32
60,000
63,500
68,000
73,000
78,500
33
64,000
68,500
74,000
79,000
34
64,500
69,000
74,500
80,000
35
65,500
70,000
75,000
36
Exception: See subsection (c), this section
(66,000)
70,500
75,500
37
(66,500)
71,000
76,000
38
(67,500)
72,000
77,000
39
68,000
72,500
77,500
40
68,500
73,000
78,000
41
69,500
73,500
78,500
42
70,000
74,000
79,000
43
70,500
75,000
80,000
44
71,500
75,500
45
72,000
76,000
46
72,500
76,500
47
73,500
77,500
48
74,000
78,000
49
74,500
78,500
50
75,500
79,000
51
76,000
80,000
52
76,500
53
77,500
54
78,000
55
78,500
56
79,500
57
80,000
(e) The gross weight of any vehicle or combination of vehicles may not exceed the following limits:
Number of axles
Gross weight (in pounds)
Three or less
55,000
Four
66,000
Five as provided for in § 13-916 or § 13-923 of this article
80,000
(f) A trailer with metal tires and a gross weight of more than 6,000 pounds may not be moved on a highway.
(g)
1. (1) Except on interstate highways, a single unit vehicle with 3 axles, or a combination of vehicles with a trailer less than 32 feet long or a semitrailer less than 45 feet long, either registered as a farm vehicle or carrying farm products as defined under § 10-601 of the Agriculture Article that were loaded in fields or other off-highway locations, is permitted an axle load limit tolerance of 5% from subsections (c) and (d) of this section, except during harvest time when an axle load limit tolerance of 15% or, subject to paragraph (2) of this subsection, a gross vehicle weight tolerance of 5% from subsections (c) and (d) of this section is permitted for a vehicle carrying the following agricultural products:
  1. (i) Wheat, for the period from June 1 to August 15;
  2. (ii) Corn, for the period from July 1 to December 1;
  3. (iii) Soybeans, for the period from September 1 to December 31; and
  4. (iv) Vegetable crops, for the period from June 1 to October 31.
2. (2) The harvest time gross vehicle weight limit tolerance of 5% under paragraph (1) of this subsection applies only to a vehicle traveling within 100 miles of the field or other off-highway location where the vehicle was loaded.
3. (3)
  1. (i) Except on interstate highways, a single unit vehicle with at least 3 axles or a combination of vehicles with a trailer length of less than 32 feet carrying forest products that have been loaded in forests or other similar off-highway locations is permitted an axle load limit tolerance of 10% from subsections (c) and (d) of this section, except for the period from June 1 through September 30 when an axle load limit tolerance of 15% from subsections (c) and (d) of this section is permitted.
  2. (ii) Except on interstate highways, a combination of vehicles with a semitrailer length of 45 feet or less carrying forest products that have been loaded in forests or other similar off-highway locations is permitted an axle load limit tolerance of 5% from subsections (c) and (d) of this section, except for the period from June 1 through September 30 when an axle load limit tolerance of 15% from subsections (c) and (d) of this section is permitted.
(h)
1. (1) Any vehicle that uses an auxiliary power unit or an idle-reduction technology unit in order to promote reduction of fuel use and emissions from engine idling shall be allowed up to an additional 550 pounds total in gross, axle, tandem, or bridge formula weight limits.
2. (2) To be eligible for the additional weight limit allowed under paragraph (1) of this subsection, the vehicle operator must:
  1. (i) Obtain and make available to law enforcement officers written certification of the weight of the auxiliary power unit or idle-reduction technology unit; and
  2. (ii) By demonstration or certification, prove that the idle-reduction technology unit is fully functional at all times.
3. (3) The additional weight limit allowed under paragraph (1) of this subsection may not exceed the certified weight of the auxiliary power unit or idle-reduction technology unit.
(i) Notwithstanding any other provision of this section, the gross vehicle weight of a vehicle for which a permit is issued under § 24-113.3 of this subtitle for traveling along a designated heavy weight port corridor may not exceed 100,000 pounds.

Added by Acts 1977, c. 14, § 2, eff. July 1, 1977. Amended by Acts 1980, c. 539; Acts 1983, c. 537; Acts 1984, c. 742; Acts 1986, c. 761; Acts 1986, c. 824; Acts 1987, c. 654; Acts 1990, c. 556; Acts 1991, c. 460, § 1; Acts 1992, c. 22, §§ 4, 5; Acts 1992, c. 482; Acts 1999, c. 30, § 1, eff. Oct. 1, 1999; Acts 2001, c. 404, § 1, eff. Oct. 1, 2001; Acts 2011, c. 100, § 1, eff. Oct. 1, 2011; Acts 2014, c. 13, § 1, eff. Oct. 1, 2014; Acts 2018, c. 494, § 1, eff. June 1, 2018; Acts 2018, c. 495, § 1, eff. June 1, 2018; Acts 2019, c. 254, § 1, eff. Oct. 1, 2019; Acts 2019, c. 255, § 1, eff. Oct. 1, 2019.