A wave of collisions in which vehicles hit pedestrians and bicyclists piqued public attention last fall and left plenty of local residents scratching their heads as they tried to explain the trend, but a statistical review of the situation provides some answers.
In 2010, there were 25 vehicle-pedestrian collisions, compared with 27 in 2009. Last year's total was the third lowest in the past 11 years, but 10 of them occurred during just two months -?September and October.
Correspondingly, there were 25 vehicle-bicycle collisions last year, compared with 35 the previous year. The 2010 total was the lowest in the past 11 years, but nine of them occurred in just three months - March, July and September.
Bicyclists were injured in 23 of the 25 accidents in 2010, and pedestrians were injured in all 25 accidents.
The most combined vehicle-pedestrian and vehicle-bicycle accidents in 2010 took place in September and October, when 15 of these accidents occurred, several of them in crosswalks.
"If this hadn't happened, we would have seen a significant reduction in these accidents last year. That would have been unusual," said Sgt. Ken Savano of the Petaluma Police Department.
After several accidents involving bicyclists and pedestrians occurred in the early fall of last year, the police department conducted a crosswalk-enforcement undercover operation throughout the city on Sept. 23 that resulted in 16 drivers being cited.
Savano explained why the accident totals rise in the fall.
"During September and October, schools have just opened, so more students are out walking and bicycling. We inevitably see increases in vehicle accidents involving pedestrians and bicyclists during this time, so we ramp up our enforcement and traffic safety education through Back to School Nights and Safe Routes to School programs."
Savano feels that the sun also plays a role in vehicle accidents during the fall and winter months.
"The sun typically drops lower on the horizon, and in some crosswalks, this can be an issue," Savano said.
The spike in vehicle-bicycle accidents in March might be attributed to people just starting to use their bicycles after the winter, he said.
"And they have been out of practice," Savano said.
Data suggests that throughout the year, the heightened activity on school days might cause accident totals to rise, particularly vehicle-bicycle accidents.
Vehicle-pedestrian collisions were fairly evenly distributed by day of week, with five occurring on both Tuesday and Saturday, four on Monday, Thursday and Friday, three on Wednesday and none on Sunday. Vehicle-bicycle accidents, on the other hand, were not as evenly balanced, with six taking place on both Tuesday and Friday, five on Monday, four on Thursday, three on Wednesday, one on Sunday and none on Saturday.
The main times when vehicle-pedestrian accidents occurred was 6 to 9 a.m., generally before schools open, and 3 to 5 p.m., after schools let out. Fifteen of the 25 vehicle-bicycle collisions occurred from 7 to 9 a.m. and from 2 to 4 p.m.
Two vehicle-bicycle accidents took place at the intersection of North McDowell Boulevard and Sunrise Parkway, and 23 accidents occurred at other locations. Two vehicle-pedestrian accidents happened at the Petaluma Boulevard North-Western Avenue intersection, and 23 took place at other spots.
Both a vehicle-bicycle and a vehicle-pedestrian accident occurred at the Western Avenue-Kentucky Street and Sonoma Mountain Parkway-Ely Road intersections.
Eleven of the vehicle-pedestrian accidents were primarily due to a right-of-way violation by drivers, followed by right-of-way violations by pedestrians (three).
"Motorists are reminded that drivers are required to stop at marked and unmarked crosswalks, and yield the right of way to pedestrians," Savano said. "If a vehicle has stopped at a marked crosswalk, drivers are required to stop and not pass the stopped vehicle, even if they cannot see any pedestrians."
Five of the vehicle-bicycle accidents were caused by right-of-way violations by bicyclists, while four were due to bicyclists or drivers not obeying traffic signals and signs, and four were caused by other hazardous movements.
Traffic collisions in Petaluma, in general, declined markedly last year, from 847 in 2009 to 633. This was the lowest total during the 25 years that the police department has been tracking annual collision statistics and is part of a steady decline since 2001, when there were 1,168 collisions.
"Overall, traffic collisions in the state have been on a downward trend, but what is notable is that our pace of decrease is faster than the statewide pace," Savano said. "Collisions in Petaluma have dropped 36 percent from five years ago, when there were 912. There are more people and more cars on the road, so we're not only thankful, but surprised by the decline."
He attributes the reduction to several factors.
"We have had a much more proactive approach to enforcement, worked closely with city engineering personnel to address traffic safety issues and have worked with the media to better educate the motoring public," Savano said. "We call engineering, enforcement and education the &‘Three "Es," but a fourth &‘E' has evolved - emergency medical services."
The police department addresses traffic safety issues by compiling statistical reports of accidents, and then analyzing data to decipher patterns and determine possible causes.
"We meet each month, and use data to find out where the problem locations are, and what is causing the problems," Savano said.
(Contact Dan Johnson at dan.johnson@arguscourier.com)
UPDATED: Please read and follow our commenting policy: