This research investigates the effect of pedestrian countdown signals (PCS devices) on crossing walking speed of pedestrians at urban signalized intersections. The research considers two age groups: (1) younger pedestrians (ages 20 to 64); and (2) older pedestrians (ages 65 and older). Two pedestrian walking speeds were used for this research: (1) crossing walking speed (speed pedestrians walk crossing a signalized intersection); and (2) normal walking speed (speed pedestrians walk a segment of sidewalk). The research found that PCS devices have an effect on a pedestrians’ crossing walking speed, regardless of age, by decreasing the speed. Older pedestrians alter their walking speed after the installation of PCS devices more than younger pedestrians. Furthermore, after the installation of PCS devices the walking speed of pedestrians shifts from a faster crossing walking speed towards a slower normal walking speed.