Red-light cameras have spread rapidly across the suburbs with the promise that they will make the roads safer.

But a Daily Herald investigation reveals serious questions about whether cameras are being placed where they are likely to reduce crashes - or where they'll raise the most cash from unsuspecting drivers.

With at least 84 cameras now up in 28 North, West and Northwest suburbs, the dramatic expansion of this technology is largely going unchecked. And as questions emerge about the fairness of the system, companies that operate the cameras and local governments are reaping millions of dollars through automated fines.

Consider:

• Most of the $100 red-light tickets are issued for turning right without coming to a complete stop. Traffic experts question the value of making this such a high priority, since it results in few serious accidents.

• A number of towns want to put cameras at intersections that don't appear to have a problem with red-light related crashes. In some cases, cameras are now at intersections that have only one or two crashes a year linked to red-light violations.

• The appeals process used across the suburbs is so varied, the Daily Herald found some towns have never thrown out a ticket while others reverse up to a quarter of all those contested.

• The focus on right-turn violations and low-crash sites not only calls into question the motive for placing cameras, but also undermines efforts to determine if they are actually working to improve safety.

The Daily Herald's investigation has prompted experts to call for an oversight board to keep an eye on where red-light cameras are installed and impose a set of standards for their use.

The series

Today: Fair? Right-turn violations account for the majority of tickets issued in most suburbs with red-light cameras.

This week:

Justified? The Daily Herald examines why intersections without an apparent problem with red-light related crashes are getting cameras.

Working? A look at how little local data exists to determine if these cameras are improving safety as they spread across the suburbs. Plus, are you ready for speed cameras? The red-light camera companies are.

Your stories: Do you have story to tell about red-light cameras? Please email it to jryan@dailyherald.com or mpyke@dailyherald.com.