Layered elastic theory (LET) has been the preferred method of analysis of asphalt pavements in highways and airports since its introduction by Burmister in 1943. In the last decade, several authors proposed new developments for the numerical solution and software implementation of LET by making improvements in the number of layers, number of loads, and number of analysis points. The new developments consider complex-load combinations and enhance the numerical integration procedure of the Bessel product functions. The accuracy of near-to-surface structural responses and the speed of computations are critical in the use of LET in the new MEPDG and any future design methods related to surface responses and damage prediction. The authors developed UNLEA, a Scilab program script for the solution of the multilayered system based on the stress function proposed by Huang. The authors apply spline integration instead of the conventional integration-summation (ISE) to solve the Hankel inverse transforms. Also, the authors apply spline interpolation in an independent module based on the Ahlvin and Ulery solutions to improve the near surface responses with the half-space transformation proposed by Khazanovich. The obtained results appear satisfactory compared with other software like KENPAVE and JULEA. The script may be implemented in other Scilab-based solutions for highways and airport pavements or geotechnical engineering.