STREETSCAPE GUIDANCE

HOME
INTRODUCTION
PART A
A vision for London’s streets
PART B
From strategy to delivery
PART C
New measures for new challenges
PART D
Balancing priorities
PART F
Appendix
PART E
Physical design and materials
SECTION 6
Introduction
SECTION 7
High quality footways
SECTION 8
Carriageways
SECTION 9
Crossings
SECTION 10
Kerbside activity
SECTION 11
Footway amenities
SECTION 12
Safety and functionality
SECTION 13
Street environment
SECTION 14
Transport interchanges
Streetscape Guidance
[Part E – Physical design and materials] Street environment 291
Porous pavement trial
London, UK
Water attenuation for safer streets
Key functions
Opportunity
Porous pavements offer highway authorities and
developers a new tool to manage stormwater by
allowing it to drain through the pavement surface
into a stone recharge bed and infiltrate into the
soils below.
Benefits
Porous materials remove excess water from
carriageways and footways, improving driving
conditions in wet weather and reducing splashing
from moving vehicles.
Implementation
Porous pavements work by providing the water
with a place to go, usually in the form of an
underlying, open-graded stone bed. As the water
drains through the porous asphalt and into the
stone bed, it slowly infiltrates into the soil or to
an attenuation system. The stone bed size and
depth must be designed so that the water level
never rises into the asphalt. This stone bed,
often 450mm to 900mm in depth, provides a
tremendous subbase for the asphalt paving.
Image courtesy of Wolf Paving
Company, Inc.
Applying in London
Porous pavements are being trialled
on the TLRN to determine if their
use is appropriate and under what
circumstances. We will publish results
when the trial is complete.