Parents of children attending Bowes primary school say that a nearby toucan crossing on the North Circular Road is "dangerous" because it does not give pedestrians enough time to cross.
Appeals to Transport for London (TfL) and Enfield Council to provide safety improvements to the crossing, near the junction with Warwick Road, are being supported by local Liberal Democrats.
The Lib Dems say that pedestrians only get nine seconds of green time to cross the A406 westbound carriageway and when trying to reach the south side of the road find themselves stranded on a narrow central island between four lanes of fast moving traffic.
Local parent Steven Adderley said: "I’m astonished that anyone at either TfL or Enfield Council would think nine seconds to cross a busy dual carriage-way was appropriate. The island is extremely narrow and, given how fidgety some children can be, this is a clear safety risk.
"Unsurprisingly, many parents in a hurry will cross when the red lights are showing, but before traffic starts moving on the westbound side of the North Circular. The safety risks of doing this are obvious, but the practice also sends dangerously mixed messages to children, who may not be able to judge risks for themselves."
After Mr Adderley contacted TfL in April, a customer service adviser wrote to say that his complaint had been passed to a specialist team who had subsequently altered the timing, though only during school run periods, and had provided the following comment:
"It seems that 22 seconds is the standard phase that’s used during school time hours. This will at times be slightly extended due to the level of demand. At other times, such as during the night, the phasing would be a lot shorter."
However, Mr Adderley and the Lib Dems say that have subsequently checked timings several times and claim that the crossing still only gives pedestrians nine seconds.
Lauren Fulbright, Lib Dem parliamentary spokesperson for Enfield Southgate, said that her party would raise the issue in the London Assembly.
She added: "We are disappointed that despite claiming to have increased the time available to cross, this appears not to have been carried out, and feel that this improved time should be provided throughout the day, not just at school times."
In response to an enquiry from Local Democracy Reporter Simon Allin, a TfL spokesperson said: "Reducing danger on roads across the capital is a vital part of our Vision Zero commitment to eliminate death and serious injury. We are looking into potential changes to the setup of the two crossings and will discuss any changes to this junction with Enfield Council."