“…However, since the early 1980s, studies included aspects of elastic demand in modeling the TRNDP (Hasselstrom, 1981;Kocur and Hendrickson, 1982 Schonfeld (1991,1993a,b) and Spacovic et al (1994) estimated demand as a direct function of travel times and fares with respect to their elasticities, while Chien and Spacovic (2001), followed the same approach assuming that demand is additionally affected by headways, route spacing and fares. Finally, studies by Leblanc (1988), Imam (1998), Cipriani et al (2004), Lee and Vuchic (2005) and Fan and Machemehl (2006a) based demand estimation on mode choice models for estimating transit demand as a function of total demand for travel.…”