howell street bus lane analysis

8/6/2019 Howell Street Bus Lane Analysis

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MEMORANDUMDate: January 6, 2010 TG: 08099.00

To: Nuru Tuku, Seattle Department of Transportation

From: Mike Swenson, Transpo

Jesse Birchman

cc: Mike Boonsripisal, King County Metro

Subject: Howell Street Transit Lane Alternatives Analysis Arterial Travel Time Results

This memorandum presents the arterial travel time/speed results for the analysis of BAT/TransitOnly lanes along Howell Street in Seattle, WA. At the request of Seattle Department ofTransportation Staff (SDOT), the arterial travel time/speed results for the Howell Street andStewart Street corridors were output from the Synchro models used for the analysis presented inthe December 9, 2010 analysis summary memorandum which subsequently were resubmitted viaemail

1with minor edits made based on comments from SDOT staff. The forecast arterial travel

time/speed results are shown in Table 1.

Table 1. Average Arterial Travel Time (m:ss) & Speed (mph)

Alternative

AM Peak Hour PM Peak Hour

EB

Howell

WB

Howell

WB

Stewart

EB

Howell

WB

Howell

WB

Stewart

Existing7.0 mph

3:49

6.0 mph

3:23

6.3 mph

2:58

5.9 mph

4:31

5.3 mph

3:47

5.6 mph

3:21

Alt 1

No Contra & BAT Lane on N Curb

7.3 mph

3:39

-6.7 mph

2:50

6.4 mph

4:11

-8.6 mph

2:11Alt 2

With Contra & BAT Lane on 2nd Lane from S Curb- - -

3.6 mph

7:27

6.3 mph

3:13

8.6 mph

2:12

Alt 3

No Contra & BAT Lane on 2nd Lane from S Curb

7.6 mph

3:32-

6.7 mph

2:49

6.8 mph

3:57-

8.2 mph

2:17

The arterial operations results presented in Table 1 are similar to the LOS results presented todate. All alternatives improve arterial travel speeds relative to existing conditions except forAlternative 2, and Alternative 3 provides the greatest overall benefit to general purpose traffic. As

the results of the LOS analysis indicated, Alternative 3 allows for improved transit travel times andreliability with the smallest impact to general purpose traffic within the study area.

Note that due to the limitations of the Synchro/LOS analysis, the direct impact of therecommended alternative on transit travel times and reliability has not been quantified in Table 1.As discussed in the previous memorandum, the existing conditions VISSIM model which modelsthe unique traffic operations along the Howell Street corridor is available should the direct impacts


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N

M:\08\08099 KC Speed & Reliability Program\WO6 - Howell Analysis\Graphics\CAD\08099_WO6_graphic01 jesseb 12/02/10 11:25

Alternative 1 - No Howell Street Contra-Flow Lane & North Curb Bus Only Lane

9thAve

TerryAve

BorenAve

MinorAve

YaleAve

Howell Street BAT/Transit Only Lane


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Alternative 2 - Maintain Howell Street Contra-Flow Lane & Bus Only Lane in Second Lane from South Curb

N


9thAve

TerryAve

BorenAve

MinorAve

YaleAve


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Alternative 3 - No Howell Street Contra-Flow Lane & Bus Only Lane in Second Lane from South Curb

N


9thAve

TerryAve

BorenAve

MinorAve

YaleAve

howell street bus lane analysis

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