The solar reflectivity was continuously monitored over time in one year (fall 2011 to summer 2012) on a permeable asphalt pavement (B2). The albedo on three days of each season is plotted in Fig. 8. As seen from Fig. 8, there is no significant change of the measured mid-day albedo over season in a year, except a slightly higher albedo shown in winter (Fig. 8(b)) when the angle of the sun is lower.To verify the impact of season on albedo, the albedos at different times of day on one clear day for each month in one year are plotted against time in Fig. 9. As found previously, the albedo measured in early morning and late afternoon is higher than that of mid-day. The mid-day albedo (11:00–15:00 in summer, 12:00–15:00 in winter) will be lower and constant over time (falling in one curve in Fig. 9). As observed from Fig. 8, it is noted from Fig. 9 that the mid-day albedo does not significantly change over season, except slightly higher in wintertime.