The rise of computers helped lead to the adoption of the slashed zero, as programmers had trouble differentiating it from the letter O on the low-resolution screens of the time. Now, that same character is actually causing computer problems, specifically with license plate readers on the Pennsylvania Turnpike, reports NBC 10.
The number zero and the letter O look a lot alike, especially on license plates speeding down the highway. Pennsylvania has tried to fix that issue on its new Liberty Bell plates by adding a slash to its zero to give it a unique look.
Unfortunately, this clarification has caused a whole new problem, with Pennsylvania Turnpike license plate readers now mistaking the new zero for the number eight. The slash across the center of the number, rather than diagonally across the entire digit, looks close enough to an eight for automated license plate reader software to mix up the numbers, especially at highway speeds with low resolution cameras. That’s probably not going to get anyone wrongfully accused of a drive-by shooting, but it is billing the wrong people for tolls, which is basically the only job these toll readers have — and they can’t do it correctly.
Substituting one problem for another
Pennsylvania has joined other states in offering a new license plate design celebrating the country’s 250th anniversary. Rather than making it a specialized plate, like Massachusetts, the Keystone State has adopted the new Liberty Bell design as its standard issue plate, an appropriate choice since this is the cracked bell’s home. Although it’s part of an attractive license plate design, officials have admitted that rolling out the new slashed zero has not gone entirely according to plan.Â
“It’s really customary with any agency that uses the LPR technology, not just the tolling industry,” Marissa Orbanek, press secretary for the Pennsylvania Turnpike, told CBS News. It’s not particularly reassuring when the agency responsible for reading and collecting tolls responds to an issue like this with essentially, “Yeah, it happens.”
PennDOT released a more descriptive statement about the issue. From 6ABC:
“The new plate design meets PennDOT production and legibility requirements and was developed in consultation with PA State Police (PSP) and the PA Turnpike (PTC). The addition of the slash through the zero was intended to help differentiate between the zero and the letter O, which both the license plate readers (LPR) and human eye have had difficulty differentiating on past registration plates. The use of the zero with a slash was also a best practice recommendation by the American Association of Motor Vehicle Administrators (AAMVA) which includes representation from jurisdictions, including law enforcement, across North America.”
Did you get the memo?
I was unable to find any specific reference to the slashed zero on the AAMVA website. However, I did see the following advice in its License Plate Standard, Edition 3:
…if an issuing authority is considering using characters such as A and R (alpha/alpha), 8 and B (numeric/alpha), O, Q, and 0 (alpha, alpha, and numeric), 1/L/I (numeric/alpha/alpha), and S/5(alpha/numeric) they must be easily distinguishable from each other. The issuing authority should consult with law enforcement officials, toll authorities, parking control authorities, and other stakeholders in their jurisdiction to identify concerns or difficulties reading license plate characters.
Turnpike authorities say that over time, the system will learn the difference between the numbers eight and zero on the Liberty Bell plate, and mistakes like this should no longer happen. But what was the point of making this change to solve a readability issue while introducing a new one in its place? Did no one test the new zero to make sure license plate readers would read it correctly? Is there something PennDOT isn’t telling us? It wouldn’t be the first time.
It seems to me that this may not have happened if the slash were more of a diagonal line across the entire digit, like on an old computer screen, instead of the small slash across the center that PA used. That would eliminate the resemblance to the number eight while continuing to solve the resemblance to the letter O. But what do I know?
