Why are Texas cops writing fewer traffic tickets?

A story by Scott Goldstein at the Dallas Morning News ("Dallas police tickets fall by tens of thousands," Feb. 28, behind paywall) opened:

Dallas police issued almost 59,000 fewer tickets last fiscal year than in the previous year, continuing a dramatic decline that could equate to millions of dollars less in city revenue, according to public records.

Police officials in Dallas, as in other cities reporting similar declines, offer several possible explanations for the decline in citations, most of which are generated by traffic stops.

They also emphasize that the number of traffic stops has gone up by tens of thousands, even as the number of tickets has dropped.

“We’re more interested in traffic stops, not necessarily citations,” Dallas Police Assistant Chief Tom Lawrence said. “The issuing of citations to a driver has always been the discretion of the officer, and we continue to be that way. We’re not going to change that.”

Tickets issued dropped by 67,000 in fiscal 2007-08, an additional 43,000 the next year and 18,000 in 2009-10. The total in fiscal 2006-07 was about 479,500, compared with 292,683 last year.

Lawrence said more than half of last year’s decrease is attributable to a 30 percent cut to a grant that financed officer overtime to work traffic enforcement exclusively in specified areas.

Police officials said that the federal grant is funneled through the state and that they did not know why it was cut.

Officers have other possible reasons for the decline in tickets.

Some officers say they are reluctant to write as many because they aren’t getting overtime pay for court appearances and because the citations they do write have gotten increased scrutiny from supervisors after ticket-writing scandals in recent years.

In addition, traffic unit personnel have been assigned recently to crime-fighting initiatives rather than strict traffic enforcement duties.

The decline comes as the city has seen an unprecedented eight straight years of overall crime reduction. For most of that time, the size of the force was steadily rising, thanks to a hiring push.

What's remarkable is not just this year's drop but the overall 39% decline since '06-'07. Wondering if the same trend is occurring statewide, Grits pulled the total number of new, non-parking traffic cases filed in municipal courts in recent years from the Office of Court Administration's annual reports. I was surprised to find that FY 2011 numbers reported represented a remarkable drop of more than 600,000 traffic tickets per year, more than 10%, compared to FY 2008:

Total new non-parking traffic cases filed statewide in Texas municipal courts:

2006: 5,711,966
2007: 5,581,607
2008: 5,749,780
2009: 5,684,813
2010: 5,521,029
2011: 5,148,510

Some police departments - notably Austin's - view traffic stops as their primary anti-crime strategy, particularly in so-called "hotspots," so I was surprised to notice that trend. It has budget implications, certainly, but more importantly, what is causing it? Are police deployment patterns changing, and if so, how and why? Perhaps the price of gas and a depressed economy are just making people drive less, which could make the trend meaningless if the economy picks back up. Perhaps Dallas' remarkable drop explains a disproportionate share of the total. OTOH, perhaps other cities, like Big D, are scaling back traffic enforcement in tight budget times because of limited resources. Or maybe there's something bigger going on, just as we've witnessed a steady drop in index crime rates over the last two decades.

Why are Texas cops writing fewer traffic tickets? What do you think is going on?