2009 Gulf Traffic

Applying Principles of thePlan Abu Dhabi 2030Urban Street Design ManualToolbox of Connectivity
Using
An Abu Dhabi Emirate Demonstration
*
* Trademarks provided under license from ESRI.

North Wathba Demonstration
Using RDI Desktop to demonstrate functional implementation of the Abu Dhabi Urban Street Design Manual for North Wathba Master Plan area connectivity:
Comparing North Wathba Neighborhood Plan to existing Abu Dhabi neighborhood
Measuring connectivity to LRT station and the importance of sikkas
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What is the RDI?
The Route DirectnessIndex (RDI) can be used to quantify how well a street network connects destinations.
The RDI can be measured separately for motorized and non-motorized travel, taking into account non-motorized shortcuts, such as paths that connect cul-de-sacs, and barriers such as highways and streets that lack sidewalks.
The RDI is calculated by dividing direct travel distances by actual travel distances. For example, if streets are connected, have good sidewalks, and blocks are relatively small, people can travel nearly directly to destinations, resulting in a high index. If the street network has many unconnected dead-ends and blocks are large, people must travel farther to reach destinations, resulting in a low index.
RDI DesktopTM includes RDI scoring, one of four sub-models to measure non-motorized system.

Abu Dhabi Urban Street Design Manual
Abu Dhabi Urban Street Design Manual defines Direct Route Index
Same theory and similar measure to RDI DesktopTM(only numerator & denominator flipped)

The Modern Sikka
Traditional Arab pedestrian access routes
Historically sized at about 3.2 meters wide – sufficient for passage of two laden camels
Developed
Under-developed

Existing Neighborhood
Comparative Assessment of RDI DesktopTM
Existing Abu Dhabi Neighborhood
Airport Road
23rd Street
25th Street
Khaleej Al Arabi

Poor-Fair RDI scores reflecting limited internal routes and external boulevard crossings
Neighborhood RDI Score
RDI DesktopTM Metric
Poor
Fair
Parcel
Parcel
Excellent
Average RDI Score:
Fair
.65

Existing Sikkas are typically underdeveloped
Underdeveloped Sikka

North Wathba Neighborhood
Neighborhood design:
Mixture of villa plot size
Neighborhood centers
Maximized public realm for non-motorized connectivity through:
Quality street pedestrian zone
Connecting Sikkas, park/open space and fareej

Measured withoutSikka connections
Good-Excellent RDI scores
Poor
Fair
Parcel
Parcel
Excellent
Average RDI Score:
Fair
.65

Measured withSikka connections
Good-Excellent to excellent RDI scores
Poor
Fair
Excellent
Parcel
Parcel
Average RDI Score:
Good
.73

Comparative RDI Scoring
RDI Score Difference: With and WithoutSikkas
Parcel
Parcel
Plots that benefit significantly by Sikka connectivity

Access to LRT Station
RDI one of several models helpful in LRT station area access and connectivity planning

RDI “Before”
Street Sidewalks Only
Poor
Fair
Parcel
LRT Station
Excellent
Average RDI Score:
Excellent
.77

RDI “After”
Street Sidewalk and SikkaNetwork
Poor
Fair
Parcel
LRT Station
Excellent
Average RDI Score:
Excellent
.79

RDI “Difference”
Plots benefiting from planned Sikkas
Plots that benefit significantly by Sikka connectivity

Distance Decay
Distance Decay is an important model to consider walking and cycling travel demand
Non-motorized network without planned Sikkas

Distance Decay
Distance Decay is an important model to consider walking and cycling travel demand
Non-motorized network with planned Sikkas

Measuring Sila’a Connectivity

Emirati Neighborhood Concept

Planned Street Layout

Sila’a Base Street And Plot Map
Converted to GIS for RDI analysis
RDI is calculated by dividing direct (“crow flight”) travel distances by actual travel distances on a scale of 0.1 – 1.0.
Streets that are well connected are patterned in small blocks, and have good sidewalks - where people can travel nearly directly to destinations thereby resulting in a higher index value.
Street networks with many unconnected dead-ends and large blocks – where people must travel farther to reach destinations thereby resulting in a lower index value.
An RDI of 1.0 is the best possible rating, indicating that pedestrians can walk directly to all destinations. An average RDI value of 0.65* is considered acceptable
Parcel
Parcel

RDI Without Sikkas
314 lots > 0.65 (62%)
Average RDI Score:
Fair
.67
Parcel
Parcel

RDI – With Sikkas
465 lots > 0.65 (92%)
Average RDI Score:
Good
.72
Parcel
Parcel

RDI Delta - With and Without Sikkas
Parcel
Parcel

Shade Route Assessment
Walk times based on street / sikka network
Walking time baseline assumption:
1.1 meter / second

Shade Route Assessment - Baseline
Baseline assumes no shaded routes.
Walking time baseline assumptions:
1.1 meter / second
Travel time to nearest Mosque
Challenge: Identifying shade routes to better connect outlying plots with neighborhood Mosques

Shade Route Assessment – Draft Plan
Walking time with newly designated shade routes assumes:
“Walking threshold increases 50% with shade” or effective travel time cut in half on shaded links.
(So “5 minutes” gets you farther with shade)

Shade Route Assessment – The Difference
Shade versus no shade difference
Parcels most benefited by shade route are noted in dark blue

Sikka Planning/Design Principles
Width – Limit width to about 3.2 meters. Wider sikkas are more difficult it is to shade for cooler micro-climates and costly to maintain
Shade sikkas by a combination use of building face, planted trees and awnings
Stagger sikka corridor alignment to enhance safety perception by avoiding a long 'tunneling' effect
Emphasize private ownership or sponsorship of adjoining sikkas - helps prevent disutility
Design sikka systems for
varied users, (a) sometimes separated use for Arab women and servants, and (b) multiple and mixed use for expatriates, school children, and transit users; and,
daily temporal change in use (morning and evening pedestrian/transit commuter, walk-to-school, mid-day shopping, mosque attendance, etc)
Establish street/settlement and sikka alignments, to the extent possible, to take advantage of sun positioning (summer vs winter) and prevailing winds

How Can RDI DesktopTM Help?
UPC Street Design Manual Implementation – measurable guidelines
Help Establish Non-motorized Neighborhood Connectivity Standards - design guide thresholds for neighborhood planning site plan review
Non-Motorized Plan Strategic Prioritization
Measure current networks - target critical non-motorized connections
Minimizing expensive and unnecessary data collection
Help expedite Draft Plan project identification and prioritization
Critical Plan Priority Analysis and Ranking – consistent and robust technique (with other sub-models) to measure important:
Neighborhood Connectors
Transit Access Connectors
Urban Boulevard Crossings

2009 Gulf Traffic

by Transpo Group on Apr 14, 2010

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