REMEMBER: WHAT CHARLIER HAS IN MIND IS AT LEAST AN INDEX OF AVAILABLE INFO TO WHICH PEOPLE CAN REFER

Study of Local and Regional Travel Patterns

Technical Memorandum:

Summary of Transportation Planning Data

in Existing Reports

Prepared for:

Regional Transportation Partnerships Project

Healthy Mountain Communities

P.O. Box 1582

Carbondale, CO 81623

970-963-5502

Prepared by:

HNTB Corporation

1600 Broadway, Suite 1300

Denver, CO 80202

Under subcontract to:

Charlier Associates, Inc.

1877 Broadway, Ste. 705

Boulder, CO 80302

February 26, 1998

Introduction

In response to development pressures and changing travel conditions, numerous transportation studies have been conducted in the Roaring Fork River Valley in recent years. The central purpose of these studies has been to evaluate existing travel conditions, to predict future conditions, and to recommend additional facilities and/or programs to respond to those changing conditions. This data summary report provides an inventory of the more recent travel data contained in these studies, an index by type of travel data, and an evaluation of how well the available data supports transportation planning requirements in the valley. The data summarized here concentrates on recent data, as the purpose of this study is to provide information in support of present and future planning. In some areas, extrapolation of historic trend data can be a useful tool in attempting to predict the future. However, as both the size and the character of the Roaring Fork Valley population has changed so dramatically in the past two decades, this technique is of limited usefulness here.

This report is made up of the following elements:

A discussion of the types of data necessary to describe and predict travel in the valley.
A general summary of available data, its sources, and the extent to which it meets planning requirements.
Highlights of the data included in available reports, and a discussion of the data’s strengths and weaknesses.
An index of the data types as included in the available reports.

The overall purpose of this report is to provide the reader with an understanding of what data is necessary, what data is available, and what data is missing and therefore must be collected to support effective transportation planning in the valley.

Data Requirements

In fast-growing areas such as the Roaring Fork Valley, increased demand for travel rapidly overloads the capacity of the transportation system. This overload leads to a variety of undesirable conditions, including highway congestion and hazard, long and inconvenient commutes for valley employees, and noise and air pollution. In attempting to improve these conditions, citizens and transportation planners propose a variety of solutions, including increased highway capacity, increased transit service, additional bicycle and pedestrian facilities, and numerous programs. Such programs (i.e., changes in parking costs) usually designed to shift travel demand from congested facilities (typically highways) and periods of the day to those less congested, or to other travel modes (typically transit.) The central challenge in planning such facilities or programs is predicting the use of the facilities and the effectiveness of the programs. In essence, the planner must attempt to predict people’s response to proposed change; that is, they must attempt to predict human behavior.

In predicting human behavior, data describing current behavior is an indispensable tool. Different kinds of people use different transportation facilities, in different ways, during different times of the day. To predict the use of transportation facilities, or the effectiveness of programs, it is necessary to understand the relationship between personal characteristics and travel choices (i.e., to know what kinds of people use what transportation facilities, and how they use them).

This relationship is often "common sense." For example, it is typical for households that own more automobiles to make more automobile trips, and to use transit less frequently than households that own fewer vehicles. Detailed data is required to turn these and other general relationships into numbers that tell, for example, how much less high-income households use transit than do low-income households, to know how many high and low income households there are in the region, and finally, to use this information to predict how many people will shift from using cars to using transit if transit service is increased.

This attempt to predict facility use requires several types of data describing current travel. In general, more detailed data is more useful, and is also more expensive to acquire. Classes of data include:

Data describing where trips come from and where they go. This data commonly is referred to as "origin-destination", and is assembled into a "trip table" in travel models. This data may be gathered and summarized at many levels of detail: the maximum level is from origin address to destination address. It also is typical to divide an area to be studied into some number of areas referred to as "zones", and to assign trip origins and destinations to them. There typically will be more such zones than there are political subdivisions such as counties, cities, and towns, and the more zones there are, the more accurate will be the results of planning based on them. In many cases, surveys are taken at the existing political subdivision level (e.g., a survey of the City of Glenwood Springs); such surveys are in most cases of limited usefulness for detailed transportation planning.

Data describing how these trips are made. This data, referred to as "mode", describes the technology used in the trip, and how that technology is employed. Possibilities include driving alone in an automobile, carpooling, riding transit, riding a bicycle, and walking. It is desirable to have specific information on how the transportation mode is used: for example, at what park&ride lot or bus stop a traveler gets onto the transit system, and the station or stop at which the traveler gets off the system at his or her destination end.

Data describing why these trips are made. People travel for a wide variety of reasons, and transportation planners group these reasons into a number of "trip purposes". Purposes include commuting (traveling from home to work or the reverse), recreation, shopping, going to school, and others. Again, people often use a different means of transportation for a different trip purpose. For example, shopping trips tend to use transit less, as people usually find it inconvenient to carry purchases such as groceries on buses or trains.

Data describing when these trips are made. As travel conditions and demand vary during the course of a typical day, transportation planners typically divide the day into several parts, most commonly the morning commute period, the afternoon commute period, and the rest of the day. Further subdivision is also possible. To perform such subdivision effectively, it is necessary when surveying travelers to ask what time trips began and ended. In areas such as the Roaring Fork Valley, travel conditions also can vary seasonally, so information on date of travel also is required.

Data describing who makes these trips. All of the data discussed above describes the trips themselves. Effective prediction of the use of proposed transit facilities also requires transportation planners to understand important characteristics of the people making the trips. These include household income, number of automobiles owned, number of adults in the household, number of adults in the home who are employed outside the home, number of children in the home, and others.

Data from all types of households. In assessing the demand for transportation facilities, it is as important to know the travel behavior of infrequent travelers as it is of frequent travelers. For example, low income households and households with few automobiles typically make fewer trips than high income households and households with many automobiles. As already discussed, however, low income households tend to make more trips on transit. To understand the demand for all transportation modes requires an understanding of the travel behavior for all types of households.

Data describing existing demand on transportation facilities. This class of data consists primarily of counts on roads, on transit facilities, and also on bicycle and pedestrian facilities. It serves as a critical "reality check" on demand estimates which transportation modelers and planners develop from the other classes of data here discussed.

Demographic Data. Data describing the number of people and households in the valley, and their location, is critically necessary to support estimates of travel demand. For example, household surveys typically develop averaged travel frequency per household based on a relatively small number of households. Estimating total demand requires that these rates be applied to all households in the area, requiring that their number and location be known.

Most surveys take a relatively small sample of the total population. That is, surveys of household characteristics only solicit information from a small fraction of the total households in the area, and surveys of travel solicit information from a small fraction of travelers. This basic nature of surveys means that it is much less effective in transportation planning to try to combine the results of several different surveys. For example, a survey of household characteristics will receive responses from a different set of people than another survey of travel; the surveys also may have been taken in different years, and conditions may have changed between them. A survey that will effectively support transportation planning should include both travel behavior and household characteristics, so that both types of information are gathered from the same people at the same time.

Available Data

The data index included in this report shows the classes of data available in the principal transportation studies reviewed for this project, and described in this report. Although numerous transportation studies and data collection efforts have been undertaken during the 1990s in the Roaring Fork Valley, a careful review of available data shows that this data is partial, fragmented, and in most cases was collected at a coarse level of detail. Different types of data are available from different sources, and are in all cases sufficiently inconsistent in structure that it is not possible to assemble them into a single, comprehensive picture of travel in the valley. Even the most detailed of these studies, the SH-82 origin-destination studies conducted by the Colorado Department of Transportation, provide only a partial view of regional travel. Available data in each of the necessary classes of data includes:

Data describing where trips come from and where they go. While no comprehensive data source exists which shows trips patterns throughout the valley, numerous studies have developed partial travel pattern data. For example, some data covers only one type of trip (i.e., work trips), some data covers only a small part of the valley (i.e., studies in the Glenwood Springs vicinity), and some data covers some transit service and not others.

Data describing how these trips are made. Numerous studies have evaluated the use of different transportation modes for some trips in the valley. The class of trips best covered in this regard are the long-distance trips along SH-82 in the valley, for which transit and automobile data is available that can feasibly be combined into a unified estimate of the percent of people making such trips that use each mode. Shorter trips are less well described, such as those which stay within or near a given town (e.g., stay within Aspen or Glenwood Springs.)

Data describing why these trips are made. Numerous studies of travel in the valley have asked people why they are making a given trip (e.g., going to work, shopping, recreation). However, most of these studies have not at the same time asked travelers where they are coming from and where they are going, so the data is of limited use in transportation planning. The notable exception is the origin-destination studies conducted by the Colorado Department of Transportation, which asked trip purpose for a large (but not complete) survey of travel in the valley.

Data describing when these trips are made. Again, the CDOT origin-destination surveys are the most comprehensive source of travel that includes time-of-day information. Traffic counts on I-70 and SH-82 also provide an overall picture of the distribution of travel throughout the day, but the data is not tied to trip origin and destination.

Data describing who makes these trips. This class of data is the weakest of all classes of data currently available in the valley. The 1990 US Census is the best source of such data, but is somewhat out of date, and does not show sufficient detail in describing the trip origin and destination location.

Data from all types of households. Several classes of households have unusual travel characteristics, particularly the poorest households, and those with at-home workers (often called "lone eagles"). Most available surveys of travel in the valley have solicited information from travelers themselves, in roadside surveys or on-board transit surveys. Such surveys will, on average, under-represent low-travel households, and travel demand estimation based on them therefore will often tend to overestimate demand, since too many low-travel households will be left out.

Data describing existing demand on transportation facilities. This class of data is reasonably complete. Numerous road counts have been taken in the valley, particularly on SH-82 and I-70, but also on many other roads. RFTA also conducts frequent surveys of its ridership, particularly on its Valley service.

Demographic Data. This class of data also is reasonably complete. Essentially all households are served by one or another utility company, and such companies keep data on the number and location of their customers.

In general, the available reports are the result of studies commissioned to answer narrow, specific questions regarding travel in the region, and the data each study gathered is thus similarly limited. Available data is particularly weak in supporting efforts to estimate the likely effects of incentive measures designed to shift travel from single occupant vehicles to other transportation choices.

Existing Studies

Roaring Fork Transit Agency Studies/Data --

1996 Valley Commuter Fare Bus Passenger Survey.

This survey gathered information on the personal characteristics of riders (income, occupation, etc.), the characteristics of their trips (trip length, bus access method, etc.), and riders’ opinions concerning existing and desired service. The survey also asked for each rider’s location of residence, and boarding and alighting stop. RFTA reports that the survey received poor response for this last question, significantly reducing the value of the survey data for detailed planning purposes.

1997 Snowmass, Two Creeks, Buttermilk, Highlands Skier Shuttle Passenger Survey.

This survey gathered personal information (income, age, occupation, tourist or resident, length of stay in the area, etc.), information on riders’ opinions of shuttle service. The study also asked riders the purpose of their trip, but did not compile information on the origin and destination of the trip, nor related information such as the how the rider got to the bus stop (walked, rode another bus, etc.)

1997 City of Aspen Fixed-Route Bus Service Passenger Survey.

This survey gathered personal information similar to the skier shuttle survey, and also gathered trip purpose information. It gathered information on riders’ place of residence, and where they got on the bus, but did not gather information on where riders’ got off the bus, and so does not link any of the information to the origin and destination of each trip.

1997 City of Aspen Galena Street Shuttle Passenger Survey.

This survey also gathered some personal information, including age, income, and occupation, and also asked trip purpose. The survey was aimed primarily soliciting tourists opinion of shuttle service. It asked where the respondent parked his/her car, but didn’t ask where the respondent got on the bus where he/she was going.

1997 City of Aspen East End Dial-A-Ride Passenger Survey.

This survey was aimed primarily at local residents, rather than tourists; most questions focused on the respondent’s work trip between home and work location in the Roaring Fork Valley, although 52% of respondents reported that their trip purpose was "social/recreational". Sixty percent of respondents reported working in downtown Aspen. Personal information was limited to respondent’s age. The bulk of the survey questions sought opinions of the existing service structure and quality, and of possible changes to it.

Spring/Summer/Fall bus schedule.

The bus schedule shows service times/frequency and stop locations.

1997 Operating and Capital Budget.

The report describes RFTA services by type, including City of Aspen services, Seasonal/Miscellaneous services, and Valley Commuter services. RFTA revenues and expenditures are described in detail. Ridership for 1995 is provided by service type and destination, and 1996 and 1997 ridership projections also are provided by service type. Actual 1996 ridership also is available.

RFTA Ridership, Service, and Cost History.

The report tracks transit ridership on a yearly basis, from 1976 to 1996. Ridership and route mileage by service category also are shown between 1991 and 1996. RFTA cost/mile is shown from 1987 to 1997.

Boarding and Alighting surveys for Highway 82 commuter services for February, March, May, and July, 1997.

These surveys show the boarding and alighting stop for each bus rider on the valley service. The results were assembled into stop-to-stop trip tables. This data is useful for detailed transportation planning, with one weakness: it does not show where people live or work, but only where they get on the bus and get off. The access portion of the trip (how people get to the bus stop) and the egress portion (how people get from the alighting stop to their destination) is of great importance in assessing, for example, the total time required to make a trip on the bus versus the time required in a car.

Existing Transportation System Report (Centennial, 1997).

The report describes the physical facilities of the RFTA system, not including its vehicles. Bus stops and park&ride lots are listed, together with detailed descriptions of them (plan view drawings and photographs). Pedestrian crossings and bicycle trails/access are also described. System ridership is described in a table of boardings and alightings by stop. Bus accident history is also described.

Contact for above reports: Dan Blankenship, Roaring Fork Transit Agency, 970-920-1905.

Four Mile Road and Glenwood Springs Alternate Route Connection to Highway 82 (HNTB, 1996).

The report describes plans and preliminary engineering for a connection between Four Mile Road and the Glenwood Springs Alternate Route (Midland Avenue), improvements to Four Mile Road, and a connection to Highway 82 including a bridge across the Roaring Fork River. Traffic conditions in the area are described in the "existing conditions" section of the report, including traffic counts and congestion conditions on SH-82, Midland Avenue, and Four Mile Road. Traffic forecasts for the year 2015 were prepared for these same roads for several road improvement alternatives. These included both volumes on roads and turning movements at intersections. Contact: Larry Thompson, City of Glenwood Springs, 970-945-2575.

Mount Sopris Transportation Project: 1993 Origin and Destination Winter Survey (1994).

Mount Sopris Transportation Project: 1992 Origin and Destination Summer Survey (1993).

Mount Sopris Transportation Project: 1994 Aspen Cordon Origin and Destination Survey (1994).

These reports describe the procedure and results of travel surveys conducted at several locations on SH-82 in the Roaring Fork Valley. The surveys were conducted by means of roadside interviews, in which a fraction of all motorists passing those points were stopped and asked a series of questions concerning themselves and their current trip. The vehicle type and occupancy, and time and date of interview were noted, and respondents were asked to describe the origin, destination, and purpose of their trip. The results of the interviews were "expanded" to represent all traffic on the road during the survey by comparing the number of interviews with the total number of vehicles passing the interview site during the interview period. This data represents the best source of detailed travel information available in the valley. Its primary weakness is related to the method of data collection. Only vehicles which passed the interview sites could be interviewed. Any vehicles which took long-distance trips along the Roaring Fork valley which by-passed the survey sites on alternate routes would be missed in the survey, as would short-distance trips which didn’t pass the survey location (for example, trips which both began and ended in Glenwood Springs, or Aspen). In addition, the survey did not include transit buses. Finally, the survey did not gather personal information from respondents. The direct tie between travel behavior and the characteristics of people making the trips is an indispensable tool in planning and forecasting travel behavior. Contact: Dave Ruble, Colorado Department of Transportation 303-757-9819.

Glenwood-Aspen Rail Corridor Feasibility Project (1995).

The study inventoried existing physical conditions along SH-82 and the existing rail corridor, and evaluated the feasibility of several rail alignment alternatives. Alternative were evaluated according to construction and operating cost, as well as expected ridership. The study did not gather significant new travel data in developing ridership estimates, but relied on existing reports, particularly the Mt. Sopris Transportation Project data described above, and population estimates and forecasts produced by state and local agencies. Contact: Colorado Department of Transportation, 970-927-9852.

Transit Development Plan for the Roaring Fork Valley (LSC, 1996).

The report describes the RFTA transit services in detail, together with travel demand in the valley, and characteristics of the valley’s population and development which affect transit demand. The study gathered little additional travel information, but provides a good summary and presentation of some of the other travel data gathered in reports described here, particularly the RFTA ridership information, the Mt. Sopris Transportation Project data, and the 1990 US Census data. Contact: Dan Blankenship, Roaring Fork Transit Agency, 970-920-1905.

Census Data Profile, City of Glenwood Springs (1995).

The report summarizes information from the 1990 US Census, describing the population of Glenwood Springs, both within the city and within the zip code. Information such as employment status, race, age, income, and education level are provided. The information is provided for the city and the zip code areas as a whole. This level of geographic detail is of limited usefulness for detailed transportation planning, but can serve as a check on total population estimates developed in more detailed planning efforts. Contact: City of Glenwood Springs, 970-945-2575.

Workers, Jobs, and Commuting Patterns in Garfield County and the Glenwood Springs Zip Code Area (1995).

The report examines employment and commuting patterns in Glenwood Springs and Garfield County, based primarily on the 1990 US Census data. While the report does not provide full "trip table" information (i.e., detailed work trip information showing origin and destination for each trip), it does provide information on commuting between town both downvalley from Glenwood Springs (New Castle, Silt, Rifle, Parachute) and upvalley towards Aspen, focusing in particular on those crossing the Grand Avenue Bridge. Contact: City of Glenwood Springs, 970-945-2575.

Glenwood Springs Alternate North/South Through Route Finding of No Significant Impact (Carter & Burgess, 1994).

The report describes the Colorado Department of Transportation’s conclusion that the proposed project to provide an alternate route through Glenwood Springs from I-70 at West Glenwood to State Highway 82 along Midland Avenue will have no significant environmental impact. The report provides no detailed description of travel patterns in the area. Contact: City of Glenwood Springs, 970-945-2575.

The Glenwood Springs Market Research Study (RRC Associates, 1994).

The report describes the results of a survey conducted in 1992 in Glenwood Springs to better understand the characteristics of visitors to the area. The survey was conducted at a number of hotels/lodges in the area, and involved analysis of registration cards; a short survey also was mailed to those hotel/lodge registrants. Information gathered included the home location of the visitors, age, income, gender, marital status, number and age of children, frequency of visits to the area, activities pursued while visiting the area, and the importance of various factors to the respondents in their decision to visit the area. Contact: Glenwood Springs Chamber Resort Association, 970-945-6589.

Eagle County 1995 and 2010 Population and Employment Estimates: Methodology and Results, Part 1 (1995), and Eagle County 2010 Population/Employment Projections (1996).

The reports provide estimates of current population, housing, and employment in Eagle County, and projections for the future. Some of the information is provided at a detailed geographic level, showing figures in the Roaring Fork Valley section of the county separate from figures for the rest of the county. Contact: George J. Roussos, Eagle County Engineer, 970-328-8600.

Revised Memorandum on Future Traffic Levels, Eagle County (LSC, 1996).

The report documents the results of travel modeling analysis conducted in the county to estimate current and predict future traffic on major county roads, including the section of SH-82 in Eagle County. Contact: George J. Roussos, Eagle County Engineer, 970-328-8600.

Inter-Mountain Transportation Planning Region: Environmental, Social, and Economic Profile (1993), and Inter-Mountain Transportation Planning Region: Existing Conditions (1993).

The reports describe past and present population and employment in the region, composed of Eagle, Garfield, Lake, Pitkin, and Summit counties. The information is derived from the US Census of 1990 and past years. Employment and population projections also are provided at the county level, based the work of the State Demographer’s Office. Information at the county level is useful for checking totals developed in more detailed transportation planning efforts. However, 1990 Census data is somewhat out of date in a rapidly changing area such as the Roaring Fork Valley. Contact: Inter-Mountain Regional Planning Commission, 970-945-8626.

Colorado Department of Transportation traffic count information, SH-82 and I-70 (1991 through 1997.) The Colorado Department of Transportation conducts an extensive, on-going program of counting traffic on roads in the Roaring Fork Valley, and throughout the state. The program includes permanent counters at three locations on SH-82 in the valley, and one on I-70 at the No Name interchange. The department also deploys temporary counters at numerous locations. Monthly average counts are available at the permanent counter locations for a number of past years. Counts by direction, by hour also are available for both the permanent counter locations and the temporary locations. This data is extensive, and provides a vital "reality check" on planning estimates of traffic. Contact: Bob Tenney, Colorado Department of Transportation, 303-757-9489.

Aspen Downtown Enhancement and Pedestrian Plan: User Survey Results and Analysis (1997).

The report documents the results of a survey of pedestrians in downtown Aspen. The survey asked respondents to describe their home location, their trip purpose, what means of transportation they used to come to downtown Aspen, their opinions of the Aspen pedestrian environment, and changes they would like to see. Contact: City of Aspen, 970-920-5000.

State Highway 82 Entrance to Aspen Draft Supplemental Environmental Impact Statement (1996).

The report documents the evaluation of four transportation alternatives for the State Highway 82 Entrance to Aspen Transportation Improvement Project, in addition to those evaluated in the original EIS. The report provides no significant new transportation survey information. Projections of highway and transit demand in the study are based on the Mt. Sopris Transportation Project studies described above. Contact: Ralph Trapani, Colorado Department of Transportation, 970-945-7629.