Thread by @SustransLondon

THREAD: The incredible benefits of low traffic neighbourhoods only materialise if people choose to walk and cycle instead of driving. If everyone continues making the same transport choices, LTNs will fail

The easiest trips to switch are the shortest ones: the school run, popping to the shops, going to the gym or to visit a friend - TfL data shows 35% of car journeys in London are under 2km

In an LTN, all properties remain accessible by car, but some short journeys become less convenient by car (e.g. a 500m car journey may become 1km, as drivers have to re-route around the modal filters), and safer on foot or cycle (as the roads are quieter), enabling mode shift

Every time someone chooses to walk or cycle instead of driving, that car trip “evaporates” from the network, leaving more space for the trips which are more difficult to switch – this is essential to the success of an LTN

Some modal filters are enforced by camera rather than planters / bollards, allowing priority access for emergency services and buses. Some local authorities are now considering using cameras to enforce all filters, and allowing a set of residents to drive through them (be exempt)

If residents are exempt from modal filters, their short car journeys will remain as convenient as they ever were, or even quicker as non-resident traffic has been removed by the LTN. Will someone stop driving their child to school if they can still drive the same direct route?

This means that an LTN with resident exemption will lead to negligible or no traffic evaporation. Road safety and air quality will improve on some streets, but traffic will simply have been displaced from filtered residential streets onto the unfiltered boundary roads

It is possible that, by reducing road capacity for cars, some non-residents may change the way they travel, but these longer trips are harder to switch to other modes, as they require long-term investments in protected bike lanes, LTNs, bus lanes, parking removal & road pricing

Exempting a set of residents risks exacerbating social inequalities, by only allowing certain people the privilege of driving certain routes. It risks creating a perception of ‘private estates’ which is likely to appeal to affluent, high car ownership areas

Exempting residents risks setting a precedent which will be hard to shake in the future. During which time, behaviours will be maintained or reinforced. Schemes already in place need to have an actionable plan for how they will develop and raise ambition through the trial phase.

Resident exemptions appear a tempting way to deliver LTNs while minimising pushback, but these schemes are unlikely to deliver mode shift, missing out on the proven health benefits of LTNs and exacerbating inequality in our communities. Let’s deliver LTNs, not private estates.