Fortunately Grosvenor Lane Carpark outside Coles is fairly safe it is mostly SWEET GUM trees that have optimal growth temperature of up to 36C unlike Plane trees that are 27C.

I initially thought all the trees were Plane trees but thank God they’re not!

The comparison below is disturbing. The Sweet Gum can be a minor irritant for a short period of time/standard seasonal allergy time but the Plane tree is constant 365 days of the year!

Sweet gum trichomes
Location: On the spiky, round fruit (aggregate capsules).
Function: These are fuzzy, hair-like structures attached to the seed-like fruits, helping to make the balls light enough for wind dispersal.
Effect on humans: Generally, not associated with any negative health effects, unlike plane trees.  

Plane tree trichomes
Location: On the "ball" or aggregate fruit, which is the source of irritant fibers.
Function: These fibers are a defense mechanism to deter animals from eating the fruit.
Effect on humans: The fibers can cause physical irritation, leading to a persistent tickle in the throat and a cough, often referred to as the "Chelsea Cough". This is a physical reaction, not an allergic one, so hayfever medication is not effective. 

Key differences
Source: Sweet gum trichomes are on the fruit, while plane tree trichomes are from the leaves and bark.
Effect: Sweet gum trichomes are primarily an irritant when the capsule bursts, while plane tree trichomes are continuously shed and can be a constant nuisance for those nearby.
Dispersal: Sweet gum trichomes are part of the seed dispersal mechanism, carried by wind and water. Plane tree trichomes continuously shed, not part of a specific dispersal event.