Traffic Analysis for Downtown West

R-K Traffic Engineering completed a Traffic Analysis (.pdf version click here) for the adjacent roadways 8th Street and West Street to the proposed Georgetown Civic Center (Downtown West) in Georgetown, Texas.

Project Description

The project consists of determining ADT for the development and distributing the estimated traffic through 8th Street and West Street. The Unified Development Code (UDC) for the City of Georgetown was used to identify the roadway classifications and ADT as defined in Table 12.03.020.

Trip Generation

The Georgetown Civic Center is anticipated to include three buildings – City Hall, GCAT (Municipal Court) and Light & Waterworks (planning, economic development and public communications). The ITE code 730 Government Office Building was used to estimate the trips for each building. The calculated 24-Hour trips per day was determined based on number of employees.

Trip Generation

[table width =”100%” style =”” responsive =”true”] [table_head] [th_column]Land Use[/th_column] [th_column]Size (Amount)[/th_column] [th_column]Size (Units)[/th_column] [th_column]24-hour[/th_column] [/table_head] [table_body] [table_row] [row_column]City Hall[/row_column] [row_column]43[/row_column] [row_column]Employees[/row_column] [row_column]514[/row_column] [/table_row] [table_row] [row_column]GCAT[/row_column] [row_column]24[/row_column] [row_column]Employees[/row_column] [row_column]287[/row_column] [/table_row] [table_row] [row_column]Light and Waterworks[/row_column] [row_column]22[/row_column] [row_column]Employees[/row_column] [row_column]263[/row_column] [/table_row] [table_row] [row_column]Total[/row_column] [row_column]89[/row_column] [row_column][/row_column] [row_column]1,064[/row_column] [/table_row] [/table_body] [/table]

Trip Distribution

24-Hour tube counts were obtained on West Street between 8th Street and 9th Street and on 8th Street between West Street and MLK. The trips estimated above were distributed throughout the surrounding roadways based on the tube count numbers and street layouts and access to major corridors. The analysis also took into account the available parking spots at each building and the proposed parking lot in the northeast corner of MLK and 8th Street.

West Street:

It is anticipated that very few vehicles would actually use West Street between 8th Street and 9th Street. This is adjacent to the proposed City Hall and provides one driveway. Another driveway is located on MLK which provides parking closer to the main entrance. It is expected that the driveway on MLK will be used more than the driveway on West.

8th Street:

8th Street between West Street and MLK was analyzed since it provides access to a number of homes to the west. The City of Georgetown Zoning Map indicates that the four properties on the north side of 8th Street are zoned General Commercial (C-3), however the use is currently residential and is anticipated to remain residential for the foreseeable future. Due to the location of the additional parking area a higher percentage of traffic is likely to use 8th Street to access this parking lot when accessing the Civic Center from Scenic Drive.

Results

ADT and Classification (Typical Weekday)

[table width =”100%” style =”” responsive =”true”] [table_head] [th_column]Roadway[/th_column] [th_column]24-hour ADT[/th_column] [th_column]Site Traffic ADT[/th_column] [th_column]Build-Out ADT[/th_column] [th_column]Roadway Classification[/th_column] [/table_head] [table_body] [table_row] [row_column]West Street[/row_column] [row_column]431[/row_column] [row_column]78[/row_column] [row_column]509[/row_column] [row_column]Local Street[/row_column] [/table_row] [table_row] [row_column]8th Street[/row_column] [row_column]713[/row_column] [row_column]348[/row_column] [row_column]1,061[/row_column] [row_column]Residential Collector[/row_column] [/table_row] [/table_body] [/table]

LOS

Further analysis was performed to estimate the Level of Service (LOS) for 8th Street. The existing 24-hour counts indicated that the peak hour was at noon in which 74 vehicles used this section of 8th Street. Using the same trip distribution assumptions above estimates 108 trips may use this section of 8th Street during the PM Peak hour. The future PM peak hour would be 182 trips. The LOS based on the 1997 HCM table “Two-Lane Roadways LOS vs Traffic Flow Rates” indicates that 8th Street will operate at LOS A during the PM peak.

Saturday

The City is also considering providing some green space, small amphitheater and a place for a Farmers Market in the Civic Center. The amphitheater is not expected to accommodate more than 150 attendees. Assuming trips both entering and exiting and a conservative vehicle occupancy rate of 2.2 persons per vehicle would estimate 136 trips during an amphitheater event. Georgetown staff expects a Farmers Market to generate no more than 300 shoppers. Assuming trips both entering and exiting and a conservative vehicle occupancy rate of 1.2 persons per vehicle would estimate 500 trips during the Farmers Market. Both estimated trip scenarios produces significantly less trips than the weekday trips. Also, 24-Hour traffic counts indicate that there is less traffic on the analyzed roadways on Saturday when compared to the weekday. In general any issues and/or recommendations for the weekday analysis is anticipated to accommodate weekend traffic.

Analysis of Results

The proposed Georgetown Civic Center will be located within the Downtown District. This area was at one time single family residential; therefore, the roads were constructed as 28’ Local Streets. At this time Georgetown does not have a roadway classification that provides a better fit for a downtown type roadway. While West Street continues to fall under the Local Street parameters, 8th Street does not. The volumes indicate a Residential Collector, but the roadway width indicates a Local Street. The UDC does allow for Residential Collector streets to be reduced to 30’ by restricting parking on one side of the road. Restricting parking on the south side would allow for a single parking lane on the north side and permit two 10’ travel lanes. While this is still just short of the 10.5’ lane widths suggested in the UDC and 2’ short of the overall street width for Residential Collectors; the roadway would still provide room for two through lanes to operate concurrently.

Recommendations

It is recommended that 8th Street between West Street and MLK prohibits parking on the south side of the road. It is also recommended that Georgetown continue to monitor traffic on the surrounding roadways. An unexpected increase in traffic volume or an increase in accidents may suggest the need for mitigation in other locations.