<ARTICLE>                     5
       
                                                
<PERIOD-TYPE>                   3-MOS        6-MOS       9-MOS
<FISCAL-YEAR-END>             dec-31-1997  dec-31-1997  dec-31-1997
<PERIOD-START>                 jan-1-1997   apr-1-1997   jul-1-1997
<PERIOD-END>                  mar-31-1997   jun-30-1997  sep-30-1997                 
<CASH>                              851         648         798                        
<SECURITIES>                          0           0           0 
<RECEIVABLES>                    48,138      51,864      54,265
<ALLOWANCES>                     (5,657)     (5,849)     (6,133)    
<INVENTORY>                           0           0           0 
<CURRENT-ASSETS>                 56,698      59,084      60,975 
<PP&E>                          183,472     196,228     205,004 
<DEPRECIATION>                  (73,220)    (76,436)    (78,528) 
<TOTAL-ASSETS>                  172,779     184,652     193,409
<CURRENT-LIABILITIES>            33,556      36,982      39,987  
<BONDS>                               0           0           0      
<PREFERRED-MANDATORY>                 0           0           0
<PREFERRED>                           0           0           0  
<COMMON>                            831         831         831  
<OTHER-SE>                       76,006      79,160      82,517  
<TOTAL-LIABILITY-AND-EQUITY>    172,779     184,652     193,409
<SALES>                          73,591      84,490      88,275  
<TOTAL-REVENUES>                 73,591      84,490      88,275  
<CGS>                                 0           0           0  
<TOTAL-COSTS>                    70,377      78,429      81,773  
<OTHER-EXPENSES>                     72          79         118  
<LOSS-PROVISION>                      0           0           0   
<INTEREST-EXPENSE>                  868         854         932                                
<INCOME-PRETAX>                   2,274       5,128       5,452   
<INCOME-TAX>                        875       1,975       2,099   
<INCOME-CONTINUING>               1,399       3,153       3,353   
<DISCONTINUED>                        0           0           0   
<EXTRAORDINARY>                       0           0           0   
<CHANGES>                             0           0           0    
<NET-INCOME>                      1,399       3,153       3,353   
<EPS-PRIMARY>                      0.17        0.38         .40   
<EPS-DILUTED>                      0.17        0.38         .40