Rental expense amounted to approximately $102,733,000 in 1996, $84,751,000 in 1995, and $72,802,000 in 1994. These amounts include $25,227,000, $27,297,000, and $31,686,000, respectively, for month-to-month rentals of revenue equipment.

The future minimum rental commitments, net of future minimum rentals to be received under noncancellable subleases, as of December 31, 1996 for all noncancellable operating leases are as follows:

                           Terminals   Equipment
                          and Retread     and
Period             Total     Plants      Other  
                          ($ thousands)

1997            $ 36,578   $ 11,712    $ 24,866
1998              22,008      8,082      13,926
1999               8,299      5,511       2,788
2000               3,212      3,065         147
2001               2,442      2,355          87
Thereafter         7,259      7,187          72 
                $ 79,798   $ 37,912    $ 41,886 

Certain of the leases are renewable for substantially the same rentals for varying periods. Future minimum rentals to be received under noncancellable subleases totaled approximately $2,337,000 at December 31, 1996.

The future minimum payments under capitalized leases at December 31, 1996, consisted of the following ($ thousands):

   1997                                     $  16,692
   1998                                        16,618
   1999                                        14,257
   2000                                         8,870
   2001                                         5,366
   Thereafter                                   6,268 
   Total minimum lease payments                68,071
   Amounts representing interest               10,109 
   Present value of net minimum lease
    included in long-term debt - Note  E    $  57,962 

Assets held under capitalized leases are included in property, plant and equipment as follows:

                                       December 31
                                    1996        1995  
                                       ($ thousands)

Revenue equipment               $  70,747   $  80,232
Land and structures                13,723      30,138 
                                   84,470     110,370
Less accumulated amortization      26,155      25,147 
                                $  58,315   $  85,223 

The revenue equipment leases have remaining terms from one to seven years and contain renewal or fixed price purchase options. The lease agreements require the lessee to pay property taxes, maintenance and operating expenses. Lease amortization is included in depreciation expense.

Capital lease obligations of $6,470,000, $25,118,000, and $15,793,000 were incurred for the years ended December 31, 1996, 1995 and 1994, respectively.