She had a greater success in road running. In the half marathon she competed at the 2001 and 2002 World Half Marathon Championships, and finished eleventh at the 2004 World Half Marathon Championships. Marconi took back-to-back victories at the Roma-Ostia Half Marathon in 2002 and 2003. As a debutant in the marathon race she won the 2003 edition of the Rome City Marathon. She finished 42nd in this event at the 2003 World Championships, and second in the 2004 Milan Marathon. In 2006, she finished 26th at the inaugural World Road Running Championships.