W2b roadway byrne

Light Rail Transit Facilities Design Course

Roadway Interfaces & Traffic Engineering 05.11.2010 & 05.12.2010

Bill Byrne, DEA

Dan Sosnovoske, Tri-Met

2


Roadway Interfaces & Traffic Engineering 3

Overview

• Right-of-way types • Alignment types • Types of protection • Traffic and pedestrian

considerations • Grade separate? • Example functional layouts • Intersection and crossing design • Traffic control strategies and

systems • Signing and signal indications • Resources



Right-of-Way Types - TCRP 17

Exclusive



Right-of-Way Types

Semi-exclusive - separate ROW



Right-of-Way Types

Semi-exclusive shared ROW with curbs and/or fences



Right-of-Way Types

Semi-exclusive shared ROW with striping or mountable curbs



Right-of-Way Types

Non-exclusive mixed traffic

Portland Streetcar



Right-of-Way Types

Non-exclusive transit or pedestrian/transit mall

Sacramento LRT

Buffalo NY LRT



Alignment Types

Semi-exclusive -Median

Boston Green Line

VTA San Jose



Alignment Types

Semi-exclusive side of street -single track (with flow)



Alignment Types

Semi-exclusive side of street - single track (contra-flow)



Alignment Types

Semi-exclusive side of street single track (reversible)



Alignment Types

Semi-exclusive side of street single track (reversible)



Alignment Types

Semi-exclusive side of street double track



Alignment Types

Semi-exclusive side of street double track



Traffic and Pedestrian Interfaces

Depend on Right of Way Type

• None for Exclusive (all RRT, some CR, some LRT)

• Limited for Semi-exclusive (CR and LRT)

• Extensive for non-exclusive (LRT)



Types of Protection

Crossings

• Passive signs

• Active signs

• Traffic signals

• Gates

• Warning devices



Traffic and Pedestrian Considerations

• Pedestrian safety

• Pedestrian access to system and adjacent properties

• Traffic safety

• Vehicular access to adjacent properties

• Traffic capacity and flow

• LRT travel time

• LRT reliability

• Passenger safety



Key Issues

• Turning vehicles

• Crossing vehicles

• Pedestrians

• Start-up



Should You Grade Separate?

Factors

• Roadway functional class and speed

• Roadway traffic volumes

• LRT headways

• LRT operating speed

• Type of traffic control

• Operating environment

• Urban design

• Cost



ITE Informational Report



DART Guidelines (1992)



Interfaces with Pedestrians

• Sight distance

• Channelization

• Crossing gates

• Bikes, wheel chairs, high heels

• Pedestrian bridges

• Development interfaces





Channelization of Pedestrian Crossings



Standard Detail of Typical Ped Z-Crossing

Business

W2b roadway byrne