The weekday patterns are not always mirrored in the morning
and afternoon periods. The two time periods do not always
have the same degree of congestion for each month, possibly
confounding the monthly weekday congestion estimates
Morning (a.m.) congestion:
• The lowest average morning congestion for all three cities is in December Weekday morning congestion is worst in Los Angeles in March, and in Chicago and Houston in September.
Afternoon (p.m.) congestion:
• Both Chicago and Houston have the lowest afternoon congestion in January, while May is the lowest for Los Angeles.
• Los Angeles’ afternoon congestion is worst in February and March, Chicago’s is worst in September, and Houston is worst in July and November.