
<TABLE> <S> <C>

<PAGE>
 
<ARTICLE> 5
<LEGEND>
THE FOLLOWING SCHEDULE CONTAINS RESTATED FINANCIAL DATA SCHEDULES FOR
THE YEAR ENDING DECEMBER 1995 THROUGH THE QUARTER ENDING SEPTEMBER 1997.
THEY ARE RESTATED FOR PRIMARY AND DILUTED EARNINGS PER SHARE FIGURES.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-END>                               SEP-30-1997
<CASH>                                               0
<SECURITIES>                                         0
<RECEIVABLES>                                   73,072<F1>
<ALLOWANCES>                                     3,533
<INVENTORY>                                      1,057
<CURRENT-ASSETS>                                79,462
<PP&E>                                         153,758<F2>
<DEPRECIATION>                                  49,308
<TOTAL-ASSETS>                                 276,597
<CURRENT-LIABILITIES>                           62,441
<BONDS>                                         74,388<F3>
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           271
<OTHER-SE>                                     136,100
<TOTAL-LIABILITY-AND-EQUITY>                   276,597
<SALES>                                        238,596<F4>
<TOTAL-REVENUES>                               267,277
<CGS>                                          156,973<F5>
<TOTAL-COSTS>                                   92,492<F6>
<OTHER-EXPENSES>                                     0<F7>
<LOSS-PROVISION>                                 1,930<F8>
<INTEREST-EXPENSE>                               1,941<F9>
<INCOME-PRETAX>                                 15,703
<INCOME-TAX>                                     2,379
<INCOME-CONTINUING>                             13,324
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    13,324
<EPS-PRIMARY>                                     0.80
<EPS-DILUTED>                                     0.76
<FN>
<F1>add back allowance
<F2>gross
<F3>total long-term debt
<F4>tolls only
<F5>network costs
<F6>total operating expenses
<F7>unusual operating expenses
<F8>bad debt expense
<F9>net
</FN>
        

</TABLE>
