Suggestions: There are various aerial lines, e.g. short, medium, long, AC or DC current, copper, aluminum, different number of phases, different conductor bundles, etc. Could you be more specific?
In the meantime
1. One way to obtain them is by calculations. E.g. see Gungor B. R. "Power Systems," Harcourt Brace Jovanovich Publishers, 1988, page 161 for the characteristic impedance for the long line (300km up) Z0=Sqrt(z/y) in equation 4-47, where z nad y are the per kilometer series impedance and shunt admittance per phase.
2. Also, "Electrical Transmission and Distribution Reference Book" by Central Station Engineers of the Westinghouse Electric Corp., 1964 shows in Table 3 "Typical Transmission Line Characteristics at 60 Cycles" on page 280 some typical values for voltages from 69kV L-L to 230kV L-L.