Birmingham City Council has issued its latest set of figures relating to the Clean Air Zone (CAZ) following its launch on June 1 and start of charges on June 14.
In July some 44,000 people were fined for non-payment of the CAZ charge in June.
The latest statistical release shows the average number of £120 penalty charge notices (PCNs) issued each working day rose from 3,393 in June to 5,126 in July.
A total of 112,772 PCNs were issued in total – of which 50,760 have been paid and 61,605 are yet to be paid.
Around one in three people subject to a charge were given a PCN for non-payment.
If all the PCNs issued in July were paid in time to reduce the charge to £60, the council would stand to make £6.7 million.
In addition, the council stands to make more than £1.9m from the remainder of the vehicles charged which were not subject to a PCN, bringing the total for the month to £8.6m.
But at the same time, the number of charges clocked up by highly-polluting vehicles entering the zone fell from 18,787 per day on average at the start of the scheme to 11,372 per day in July.
Compliance rate – the proportion of vehicles which meet emissions standards – rose from 73.8 in the first half of June to 79.9 per cent in the second half to 80.4 per cent in July.
The average number of unique vehicles detected within the zone – all roads within the A4540 Middleway Ring Road but not the Middleway itself – initially fell during June and then stayed about level in July.
An average of 100,550 vehicles entered the CAZ in the first half of June, which fell to 95,360 in the second half and stood at 95,414 in July.
Buses and coaches continue to have the highest compliance rate at 98.8 per cent in July, followed by heavy goods vehicles at 93.7 per cent and cars at 88.6 per cent.
The compliance rate of vans was 74.1 per cent in July and the rate for mini-buses was 73.2 per cent.
Birmingham City Council’s Head of the Clean Air Zone, Stephen Arnold has previously said it is hoped the percentage of people receiving a PCN will reduce as people get used to the way the scheme works.
A Birmingham City Council spokesperson said: “Birmingham’s Clean Air Zone is helping to encourage more and more drivers of some of the most polluting vehicles on our roads to do something different.
“We continue to encourage all drivers to check if they need to pay the daily fee. And if they do need to pay they can also find out about the support that is available as part of our journey to becoming a clean air city.
“Where drivers receive a penalty charge notice that they believe is incorrect they are able to submit a challenge. And the council has published clear guidance on the Brum Breathes website on where it is able to offer discretion.”
In response to a question on the number of PCNs issued in July, the spokesperson said: “The number of PCNs issued in July is correct but not all of the PCNs issued in July do not, necessarily, relate to July. Some would be from contraventions in June.
“Similarly, there is very often a lag between a contravention being issued and people paying any PCN fee – £60 if within 14 days or £120 if later.
“Very simplistically if someone received a PCN in the last two weeks of the month and they chose to contest it would show as unpaid until it was paid.
“And if we use the average number of PCNs issued per working day that could be up to 50,000 PCNs showing as ‘unpaid’ from the latter half of July.
“This is an extreme example but there is a lag which is expected to even out over time.
“The data from June reflects two weeks of operation and some of the PCNs generated at the end of June will have been issued in July.
“We do know that the daily number of contraventions being generated is reducing as more and more drivers adapt to the Clean Air Zone.”
Asked if enough is being done to signpost the scheme and how charges work, the spokesperson said: “There are currently more than 300 signs in and around the zone clearly marking it out in addition to an interactive map on the website that allows drivers to plan any routes.
“We are continuing to monitor the situation and will provide additional signage and resources as required.”
The CAZ is being implemented in response to poor air quality in the city which is responsible for a reported 900 deaths per year.
It has been reported Bath’s Clean Air Zone has seen nitrogen dioxide levels within the zone decrease by more than 12 per cent in the first quarter of operation.
A legal adviser who worked on both cities’ schemes said Birmingham’s CAZ – which charges private cars unlike Bath’s could see “greater benefits”.