Maryland Transportation Section 24-109
§ 24-109.
  (a)   (1)   In this section the following words have the meanings indicated.
    (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)   "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)   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.
  (c)   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     34,000     34,000                
and less                        
More                        
than     38,000     42,000                
8                        
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    
    Exception:                    
36     See
subsection
(b), this
        (66,000)     70,500     75,500    
37     section         (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            
  (d)   The gross weight of any vehicle or combination of vehicles may not exceed the following limits:
Number of         Gross
axles         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
  (e)   A trailer with metal tires and a gross weight of more than 6,000 pounds may not be moved on a highway.
  (f)   (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 percent from subsections (b) and (c) of this section, except during harvest time when an axle load limit tolerance of 15 percent from subsections (b) and (c) of this section is permitted for a vehicle carrying the following agricultural products:
      (i)   Wheat, for the period from June 1 to August 15;
      (ii)   Corn, for the period from July 1 to December 1;
      (iii)   Soybeans, for the period from September 1 to December 31; and
      (iv)   Vegetable crops, for the period from June 1 to October 31.
    (2)   (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 percent from subsections (b) and (c) of this section, except for the period from June 1 through September 30 when an axle load limit tolerance of 15 percent from subsections (b) and (c) of this section is permitted.
      (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 percent from subsections (b) and (c) of this section, except for the period from June 1 through September 30 when an axle load limit tolerance of 15 percent from subsections (b) and (c) of this section is permitted.