Va. Code § 58.1-2656
In making report of and assessment of the property included in the class described in § 58.1-2655, there shall be found for each railroad, for its main line or lines and for each branch line, for single and, where existing, double, triple and quadruple track and for sidetrack, the average value per mile in this Commonwealth of its track, track appurtenances and track structures, including cuts, fills, track surfacing, excavation, ballast, bridges, trestles and tunnels, but not including right-of-way lands or buildings or structures thereon other than track structures, or improvements required to be reported in other classes, and in any county, corporation or school district, the assessment of all property of such railroad included in the calculation of such average, as above provided, shall be the number of miles of its single, double, triple, quadruple or sidetrack therein, as the case may be, multiplied by the assessed average value thereof per mile. The assessed value of a railroad's track, track appurtenances and track structures in this Commonwealth shall be determined by multiplying the average of (i) the cost of such property recorded in the applicable Interstate Commerce Commission road accounts, less accumulated depreciation, and (ii) the depreciated basis of such property for federal income tax purposes by a fraction determined by dividing the railroad's track miles within the Commonwealth by its total track miles. Notwithstanding the foregoing sentence, in each of the tax years 1993, 1994, 1995 and 1996, the assessed value of a railroad's track, track appurtenances, and track structure in any county, city or town shall not be less than the 1992 assessed value therein of such property, excluding retirements.
Va. Code § 58.1-2656