UCL News


A small step for mankind

24 September 2006

It looks like something from the bowels of the Starship Enterprise: a raised platform comprised of identical geometric squares in a blackened room.

A holodeck, perhaps? …

No, PAMELA (Pedestrian Accessibility & Movement Environment Laboratory) has been set up by UCL to measure and monitor the movements of pedestrians.

The goal is to create safer pavement, safer bus stops - in fact, safer outdoor surfaces everywhere feet hit the ground.

"Everybody's journey anywhere has some sort of pedestrian element to it, even if it's walking to the car," says Professor Nick Tyler, Chadwick Professor of Civil Engineering at UCL, and the man who led the development of PAMELA. "So getting this bit right makes a difference."

Which leads one to wonder: "Is it really that bad? Are people falling down all over the place?"

Well, yes, says Tyler.

Governments know this. The British government recently assigned the national commission responsible for setting and enforcing health and safety regulations to examine the problem. …

It isn't just that people sue local governments when they trip on a sidewalk or while stepping onto a bus (and they do). Trips and falls burden the health-care system. There's also a social cost: Seniors who fall sometimes blame themselves, and in a worst-case scenario can end up as shut-ins, says Tyler.

If researchers find out why people fall - and the reasons are more complicated than you might think - they can find economical ways to help prevent falls. They can in fact, make the whole pedestrian environment safer and more pleasurable, which would in turn encourage more people to walk.

For example: After using PAMELA to simulate a bus stop, researchers learned that the further away from the curb a bus stops, the longer it takes people to board, and not simply because it takes a step or two more to get to the bus. Having to step off the curb, onto the street, then onto the bus dramatically increased stress levels in some subjects - negotiating the gap sent their heart rates soaring.

"There's a segment of the population for whom this is a significant problem," says Tyler.

Correcting the problem would reduce the stress and allow buses to run more efficiently, he says. …

PAMELA … consists of three key elements. The main one is a raised computer-controlled platform, about the size of a small two-bedroom apartment.

The platform can be altered to recreate anything from a train station to a bus stop to a shopping district. The surface can be flat, steep, wet, concrete, grass, stairs, or almost any other ordinary walking surface you can think of.

The lab also includes a lighting system and a sound system that can create ambient noise and light: a train arriving at a station, a bright morning, a rainy day.

Researchers use life-size models of things like lampposts and bus stops to recreate streetscapes.

"Real ones tend to be designed to be buried in the ground; if you just plunk them on the platform, they tend to be very unstable," says Tyler. The models are also lighter to carry.

"People forget amazingly quickly that they're not on a real street," says Tyler.

Which prompts the question: Why not use a real one?

In real life there are too many variables to control, says Tyler. With the experiments in the PAMELA lab, "We know exactly what people are reacting to."…

Francine Kopun, 'Toronto Star'