Technical Memorandum #1
Existing and Future Travel Demand Estimates

Introduction

Project Description
The Ship Creek Multi-Modal Transportation Plan is intended to be a long-range infrastructure master plan for transportation that logically integrates a number of individual development strategies for the Ship Creek area. An implementation plan will also be developed that identifies the physical improvements necessary to implement this plan, an appropriate staging program for these improvements, and an assessment of expected project costs.

The Ship Creek area lies immediately to the north of downtown Anchorage. It is roughly bounded by the downtown to the south (3^rd Avenue), by the Port of Anchorage to the north, by Elmendorf Air Force Base to the north and east, and by Knik Arm to the west.

The Ship Creek area is a truly multi-modal area in terms of transportation facilities and is currently served by road, rail, seaport and pedestrian trails. Automobiles, trucks, buses, bicycles, trains, ships and pedestrians use these facilities. In the future, ferry transportation is likely to be added to the mix of transportation modes in Ship Creek.

The major roadways serving automobile, truck, and bus traffic into and out of the Ship Creek area include the A/C Street couplet which traverses the area on a viaduct, North C Street, Ocean Dock Road which provides primary access to the Port, Whitney Road, West Bluff Road, Ship Creek Avenue (formerly Warehouse Avenue) and Post Road. Each of these surface streets is a two-lane facility with stop-controlled at-grade intersections.

The Alaska Railroad is a major component within the Ship Creek vicinity, traversing the area with lines running north to Fairbanks and south to Seward. A railway station is located in Ship Creek on Ship Creek Avenue.

Trip Projection Methodology

This memorandum presents the results of the first phase of the Ship Creek Multi-Modal Transportation plan which includes an evaluation of existing multi-modal transportation facilities, land uses, mode conflicts and estimated traffic volumes by mode. The task also included projections for year 2023 travel demand by travel mode. These projections were made by applying appropriate growth rates to existing traffic volumes. Growth rates were determined by information provided in interviews with a number of transportation facility users in the area and are based on three different development scenarios encompassing low, medium and high growth scenario assumptions.

Existing Conditions

The development of a comprehensive transportation plan begins with an assessment of the existing traffic conditions within the study area.  This data provides an inventory description of the existing traffic volumes while setting the stage for a basis of comparison to future conditions.

For the purposes of this study, information is needed that describes the various types of travel modes, how each of the local businesses utilize each of the travel modes, when they utilize each travel mode, and how they plan to use these modes in the future. To obtain a reasonably accurate assessment of the existing transportation facility usage, a majority of the larger businesses that are currently operating along the major roadway corridors within the Ship Creek study area were surveyed.  These roadway corridors include the A/C Street couplet, North C Street, Ocean Dock Road, Whitney Road, West Bluff Road, Ship Creek Avenue, and Post Road.

Northern Economics conducted a field study to develop a representative sample of businesses and organizations along these Ship Creek roadway facilities.  As a result of the field study, the names of the majority of Ship Creek businesses and organizations were obtained and categorized according to location by roadway facility as shown in Table 1.  Using this list of 44 businesses and organizations, an attempt was made to contact a representative from each business. During the interview process, the interviewee was asked to provide the following:

• A description of the various travel modes utilized on a daily basis;

• an estimate of the daily and hourly volumes associated with each mode;

• a description of the peak operating characteristics of each mode by month, day, and hour;

• a description of the transportation facilities utilized;

• potential growth rate estimates for each travel mode; and

• a description of any foreseeable events that may affect the existing or future travel volumes by each mode.

  A sample survey questionnaire is located in Appendix A.  Based on the results of the survey process, a comprehensive listing of travel modes, traffic volumes, traffic distributions, and growth projections were obtained for each Ship Creek business.  A description of the results is presented in the paragraphs below.

Table 1

Ship Creek Businesses and Organizations

Results

From the Ship Creek business/organization survey, aggregate traffic volume data was obtained for each travel mode during the peak individual operating time periods.  Based on this data, a determination was made as to which time of the year, which day of the week, and which hour of the day was likely to experience the heaviest traffic volumes.  Our analysis showed that the peak travel month occurs during the summer, and probably during the month of June or July when the combination of tourist traffic and Ship Creek fishing is heaviest.  From a day-of-week perspective, Tuesday appears to experience higher than average traffic volumes.  This situation can be attributed in part to the activities of the Port of Anchorage, which schedules container ship deliveries throughout the day.  During a July Tuesday, therefore, the peak traffic hour was found to occur during the early evening time period, particularly between the hours of 3:00 p.m. and 6:00 p.m.  Based on a comparison of past traffic counts conducted by the Alaska Department of Transportation and Public Facilities in 1997 and 1998, it was determined that the peak daily traffic occurs between the hours of 4:00 p.m. and 5:00 p.m.  A summary table of the peak hour traffic volumes by mode and roadway facility is shown in Table 2. Figure 1 graphically illustrates these same traffic volumes according to the respective roadway facilities. Table 2 and Figure 1 provide an estimate of traffic volumes that can be expected to occur during a Tuesday evening peak hour in July. 

Table 2

Existing Peak Hour Traffic Volumes by Mode and Roadway Facility

¹ The volumes in Table 2 reflect only traffic volumes generated by sampled Ship Creek businesses.

² Represents city transit buses, tour buses, and school buses operated by Laid Law

³ Indicates the number of trains crossing each roadway facility.

The truck, automobile, bus, rail, and pedestrian traffic volumes shown in Table 2 reflect volumes that are being generated solely by the sample of Ship Creek businesses and organizations.  Given the nature and level of use associated with A/C Street through the Ship Creek vicinity, this roadway link is expected to experience a significant amount of background traffic.  For the purposes of this study, background traffic is defined as the traffic that is not directly associated with Ship Creek, but may be passing through such as commuters, delivery trucks, and visitors to and from the Government Hill residential area. As shown in Figure 2, this background traffic accounts for 545 vehicle trips making up approximately 33 percent of the total roadway traffic on A/C Street.

 Along with truck, automobile, and bus traffic, rail traffic volumes are an important transportation element within the Ship Creek vicinity.  Since rail cars operate within their own right of way, the only interaction these trains have with regular street traffic occurs when rail line cross the street network.  Depending upon the length of the train, motorized vehicle traffic will experience varying degrees of delay at the rail crossings resulting in undesirable traffic operations.  Survey results indicate that as many as eight trains during the peak hour can cause truck and automobile delays, hampering the smooth and efficient operation of traffic along N. C Street and Ocean Dock Road.  Of particular significance, the railroad tracks along Ocean Dock Road cross the roadway in several locations, resulting in numerous vehicle/train interaction points.  During the identified peak time period, this can result in approximately 6 vehicle/train delay points.  Extremely long trains with numerous boxcars can cause even longer vehicle delays.

Table 2 also includes estimates of pedestrian volumes along or across the study roadway facilities. Many of the pedestrians are fishermen who fish between the Knik Dam and the Mouth of Ship Creek. According to the Alaska Department of Fish and Game, on average there are about 750 anglers per day. In addition to the anglers, there are likely to be a number of other pedestrians, including friends and/or family members of the anglers, other tourists, and Alaskans who are in the area for business or pleasure. Anecdotal reports indicate as many as 150 non-anglers may be present at any given time. Pedestrian activity is concentrated from the Knik Dam to the mouth of the creek and between the creek and various parking lots. Volumes reported include pedestrian crossings of North C Street as well as pedestrians walking along Whitney Road and Ship Creek Avenue.  Additional pedestrian activity occurs along A/C Street and Ocean Dock Road as Government Hill residents and Port workers often venture into the Downtown Anchorage area.

Other significant pedestrian generators in the area include Bean's Café/Brother Francis Shelter which serves 800 people per day on average at 8 a.m. and noon. The proposed Ship Creek Trail, which based on trail usage at the nearby Coastal Trail, can be anticipated to generate 500 to 1,000 users per day in the area between Knik Dam and Reeve Boulevard. As an aside, future trail development activities are expected to include the construction of 20 new parking stalls at Viking Drive between Orca Street and Concrete Street.

Although it is possible to determine a peak hour based on traffic volume counts, a number of other times of significant transportation activity were also identified. Traffic conditions in each of these other time periods may also need to be considered (in at least a qualitative manner) during the development of the Ship Creek Multi-Modal Transportation Plan. A description of some of these high-activity times is provided below:

• Passenger trains bringing cruise passengers to and from Anchorage arrive and depart during summer morning and evening hours, typically around 6:45 a.m., 8:15 a.m., 10:00 a.m., 8:15 p.m, 9:45 p.m., and 10:25 p.m. These trains are usually met by tour buses, taxis, and hotel shuttle buses to transfer passengers to Anchorage hotels. Anywhere from 15-30 tour buses, and 250-300 taxis, personal automobiles, and hotel shuttle buses meet each train.  During these times, there is significant pedestrian activity occurring in front of the depot and along the adjacent roadways such as 1^st Avenue and N. C Street.

• Heavy automobile volumes are experienced when Anchorage fishermen drive to Ship Creek to fish for salmon in June, July and August. These trips often coincide with high-tide, and especially after work hours in the early evening.

• A school bus yard located in Ship Creek serves the Anchorage School District. As a result, high school bus volumes are experienced in early morning hours and again around 4:00 p.m. on school weekdays. In this regard, summer volumes are significantly lower than when school is in full session.

  Based on typical ratios of peak hour-to-daily traffic volumes for the Anchorage area, approximate daily traffic volumes were generated from these peak hour estimates. These daily volume estimates are provided in Table 3.

 Table 3

Existing Daily Traffic Volumes by Mode and Roadway Facility  

 These estimated volumes may be used to compare to estimates for daily trip capacities for each facility to develop an assessment of the operational sufficiency of each facility.

Future Projections

The future truck, automobile, bus, rail, pedestrian, and bicycle traffic projections listed in this report were based on the existing traffic volumes that were assembled from the survey process.  It should be noted that these future projections are based on expected growth associated with the existing businesses located within the Ship Creek study area. As part of the next phase of this study, these future projections will change as a more detailed analysis is conducted. This will take into account the traffic growth associated with the following planned developments:

• 2001 or 2002 ferry service
• 2010 commuter rail service from the Mat-Su borough
• 2005 rail service to/from cruise ships in Seward and Whitier
• Planned expansions identified in the Regional Port of Anchorage Master Plan
• Mixed land use developments that have been identified in the Alaska Rail Road Corporation Ship Creek Master Plan

 Methodology

Future travel growth assumptions for year 2023 conditions were based on a forward projection of existing traffic volumes according to the three growth assumptions investigated as part of the interviews conducted with area businesses. As part of the interview process, each business representative was asked to provide annual traffic growth rate estimates for three scenarios: low; medium and high growth through 2023. Clearly, many of the interviewees do not typically work in the arena of long-range planning, especially in travel forecasting, so many of them had difficulty estimating a reasonable 20-year growth projection. Consequently, many of the interviewees quoted growth rates from shorter-term plans (typically, 3-, 5- or 6-year plans). In such cases, these shorter-term growth rates were used as the basis for the 2023 projections developed in this study.

The growth rate estimates obtained were compared with different growth scenario estimates developed as part of other formal planning studies in the Ship Creek area. These include plans developed for the Alaska Rail Road Corporation and the Port of Anchorage in recent years (References 1 and 2).

Description of low, medium and high growth scenarios

Based on the ranges of annual growth rates obtained in the interview process for this study and a comparison of these rates with growth scenarios from other formal studies in the Ship Creek area, the three growth scenarios developed for this study are shown in Table 4. Interestingly, these projections seem to be quite consistent with those used in the Port Master Plan, which also considered three growth scenarios ranging between –0.1 % and 3.7 percent annual growth. 

Table 4

Ship Creek Growth Scenarios

As indicated in the table, the low growth assumption results in a 27 percent growth by 2023. The medium growth scenario reflects a 61 percent growth while the high growth scenario leads to traffic volumes doubling with a 103 percent growth.

Year 2023 projections by mode and facility

Using the growth rates shown in Table 4, existing traffic volumes were multiplied to produce the results shown in Table 5 below.

Table 5

2023 Peak Hour Road Traffic Projections

As part of subsequent project activities, these estimated future volumes will be compared against the estimated capacity of each facility to determine the overall operational sufficiency of each facility under each of the different growth scenarios.

References

 1.      Alaska Railroad Corporation.  Ship Creek Development Master Plan.  January 1999.

2.      Port of Anchorage.  Regional Port of Anchorage Master Plan.  August 1999.