The speed camera outside The Illawarra Grammar School has jumped into the top three earners in the Illawarra.
Office of State Revenue data also show a spike in the number of fines in March - the first month of lockdown where NSW students went into remote learning.
It suggests motorists may have mistakenly assumed the school zones outside TIGS were no longer in force.
The camera monitors traffic in both directions on the Princes Highway outside the school.
Speeding southbound motorists alone ranked in third spot in terms of revenue with $487,933 - up more than $70,000 on 2018-19.
The top camera was northbound on the M1 Princes Motorway at Gwynneville and followed by the Windang Road, Windang camera.
... motorists may have mistakenly assumed the school zones outside TIGS were no longer in force.
The TIGS camera also picked up 1000 speeding motorists heading north, equating to $275,912 - also up on the same time last year.
Combined, the TIGS camera revenue was $763,845, $66,000 more that 2018-19.
What is most surprising is the big jump in motorists caught during school zone hours in March 2020 - the first month that NSW students were learning at home.
In March this year, southbound speeders had to cough up $61,000 in fines - an 82 per cent jump compared to March 2019.
It's a similar story for northbound motorists where March fines jumped 63 per cent to $36,240.
During the time schools brought in remote learning, school zones were still in operation because some students were still attending.
However, the spike in school zone revenue in that first month suggests some motorists figured school zones weren't operating.
The TIGS camera knocked the red-light speed camera at the Crown Street-Gladstone Avenue intersection out of the top three.
It finished in fourth spot, with $423,639 in revenue.
The bottom three cameras in terms of revenue were all in the Illawarra's northern suburbs; Memorial Drive northbound ($61,938), Princes Highway at Bulli northbound ($54,093) and Memorial Drive southbound ($37,064).
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