Study of increase in traffic tickets issued around end of month inconclusive

Added by on October 18, 2012

A researcher, Robert Picard – a student at the University of North Florida, published the results of his informal study on Thursday to address the rumor that says police issue more traffic tickets toward the end of each month to meet their quotas.

The researcher used two million records about traffic citations published by the US city of Baltimore’s Open Data Catalog.

The researcher performed various analysis and calculations to determine the number of traffic tickets the Baltimore police department may be expected to issue on a given day of the month. He then compared the expected number of tickets by day of the month with the average number of tickets by day of the month during the past three years. The result of his analysis is surprising because it appears to support the rumor.

Picard found the number of tickets issued on the 28th, 29th, and 30th of each month are higher than the anticipated number of tickets; he also found the same for the first nine days of each month. The number of tickets issued between between the 10th and 27th were lower than the number of tickets issued that may have been expected to be issued.

In his analysis Picard wrote, “So what does this mean? …. It may look like a quota system would explain the patterns we see in the data, but you could probably come up with another explanation that seems to fit the data too.”

Addressing the rumor he added, “Do the police in Baltimore give out more tickets at the end of the month to meet quotas? It seems plausible, but I don’t know more than that.”

An analyst said, “This type of expository research encourages discussion about traffic safety – it’s a great reminder that we, as drivers, need to check our driving habits to ensure we protect ourselves and others on our roads.”

Through its “OpenBaltimore” data catalog, launched in January 2011, the city of Baltimore offers files that include data about traffic violations, property tax payments, government salaries and other topics. In addition to downloadable files, the OpenBaltimore initiative provides programmers access to the data for use in custom applications. The Baltimore Sun created a web-based application that maps the locations of speed cameras.

The Open Baltimore Data Catalog is part of a larger initiative that includes 39 US states and 35 countries to democratize public sector data by providing easy access online and providing access machine readable data to support innovations in use of data and application development.

Robert Picard works as a software intern at DuckDuckGo, a search engine, and is currently studying history and computer science at the University of North Florida. Picard says he’s an amateur statistician and independently performed the research.