A vehicle trip is defined as a single directional trip that has one origin and one destination. A typical vehicular trip to the campus has an off-campus origin, enters campus and terminates in a campus parking lot. A vehicle makes a second trip when it leaves the parking lot and exits campus for an off-campus destination.

When vehicle trips "to" campus are discussed, reference is made to vehicles that are counted or estimated to be entering a campus area from a non- campus area. Likewise, vehicle trips "from" campus refers to vehicles that are counted or estimated to be leaving a campus area to a non-campus area. Note that the Annual Campus Traffic Count does not attempt to factor intra-campus trips, for example those by University vehicles, nor does it identify bus trips, trips by service vehicles, and so forth. These "to" and "from" vehicle trips have been adjusted so that they are equal for an average 24-hour average weekday daily traffic (AWDT). The number of total campus vehicle trips is the sum of the trips to and from campus.

The hourly directional volumes for each campus area were added together for the five-day period from October 18-22, 1999. This sum was divided by five to obtain the daily average hourly directional volumes and accumulated levels for each area. These area averages were added to obtain the campus (as surveyed) average hourly directional volumes, campus AWDT and hourly accumulation levels.


Summary of Survey Results

The results of the 1999 Annual Traffic Campus Count are summarized below, relative to previous years. Three periods, including the morning peak period (7:00 to 9:00 AM), the evening peak period (3:00 to 6:00 PM), and the total 24-hour period, are monitored. These are the time periods where the University is held to conditions of the GPDP. The numbers of trips to and from campus in 1999 are well below the maximum trip levels agreed upon by the University and the City of Seattle. These maximum trip levels are based on the conditions of the 1992 GPDP; they are the average numbers of the campus trips surveyed in 1988, 1989, and 1990 plus an error factor of five percent.

The number of trips have increased since 1998 among the trips to campus during the morning peak period, trips from campus during the evening peak period and the total number of trips in the 24-hour period. We observe that this can be attributed mainly to an increase in the number of trips recorded in South Campus.

Table 1. Historical Summary of Trips to and from Campus

MAIN CAMPUS: GATES 1, 2, 3 and 5

The Main Campus average adjusted daily hourly directional volumes and accumulation levels are tabulated in Table 2. Main Campus consists of Gates 1, 2, 3 and 5. The data indicate that there was an average of 15,013 trips both to and from the Main Campus daily. Peak accumulation levels occurred between 11:00 AM and 12:00 noon when 3,175 vehicles were present.

Table 2. Vehicle and Trip Volumes on Main Campus


SOUTH CAMPUS: GATES 4, 6 AND 7

South Campus average adjusted daily hourly directional volumes and accumulation levels are tabulated in Table 3. South Campus consists of Gates 4, 6 and 7. The data indicate that there was an average of 6,160 trips both to and from the South Campus daily. Peak accumulation levels occurred between 10:00 AM and 11:00 AM, when 1,530 vehicles were present.

It is noted that our measurements recorded a major increase in the number of trips in the South Campus area from the recorded levels of 1998. However, this increase does not correlate to changes in lot utilization statistics provided from Parking Services. This discrepancy is unexplained. Therefore, South Campus figures are observed to be high for 1999 and are credited for the increase in total Campus trip volumes.

Table 3. Vehicle and Trip Volumes on South Campus


STADIUM LOTS: E-10, E-11 AND E-12 (GATES 8 AND 18)

Stadium Lots E-10, E-11 and E-12 average adjusted daily hourly directional volumes and accumulation levels are tabulated in Table 4. The data indicate that there was an average of 2,646 trips both to and from the Stadium Lots daily. Peak accumulation levels occurred between 11:00 AM and 12:00 noon when 1,411 vehicles were present.

Table 4. Vehicle and Trip Volumes in Stadium Lots


MONTLAKE LOTS, E-1 AND E-5

Parking Lots E-1, E-5 average adjusted daily hourly directional volumes and accumulation levels are tabulated in Table 5. The data indicate that there was an average of 4,359 trips both to and from the Montlake Lots made daily. Peak accumulation levels occurred between 10:00 AM and 11:00 AM, when 2,781 vehicles were present.

Table 5. Vehicle and Trip Volumes in Montlake Lots


WEST CAMPUS

West Campus average adjusted daily hourly directional volumes and accumulation levels are tabulated in Table 6. The data indicate that there was an average of 1,658 trips both to and from the West Campus Lots made daily. Peak accumulation levels occurred between 10:00 AM and 11:00 AM when 1,096 vehicles were present. Complete traffic counts were conducted at the West Campus Garage but were not conducted at the various West Campus surface lots. Trip generation numbers for the West Campus surface lots were determined using the number of mid-day vacant spaces as a guide. The numbers of vehicles present in the lots were multiplied by an average parking turnover factor to determine the number of vehicle trips to and from the West Campus surface lots. The total number of vehicle trips were distributed throughout the day based on the distribution of vehicles entering and exiting the West Campus Garage.

Table 6. Vehicle and Trip Volumes in West Campus



Total Campus Results

Table 7 shows the number of vehicle trips entering and exiting the campus over a 24-hour period. The data for each of the five campus areas are combined and tabulated in Table 8 and plotted in Figure 2. The data indicate that there were an average of 29,837 trips both to and from campus daily. The peak accumulation level occurred between 10:00 AM and 11:00 AM, when 9,983 vehicles were present.

Table 7. Summary of Average Daily Trip Volumes to and from Campus

Figure 2. Average Adjusted Number of Vehicles Entering, Exiting and Accumulating on Campus

Table 8. Average Adjusted Number of Vehicles Entering, Exiting and Accumulation on Campus

History of Campus Traffic Count

Table 9 shows the campus traffic count information for the years 1990 through 1999 for all time periods and each direction. The University and the City of Seattle have agreed on three values that represent maximum trip levels for the three time periods. The periods are vehicle trips to campus from 7:00 AM to 9:00 AM, vehicle trips from campus from 3:00 PM to 6:00 PM, and 24 hour daily vehicle trips.

Table 9. History of Campus Count

Conclusions

The University continues to meet the conditions of the 1992 GPDP. The numbers of trips to campus, trips from campus, and total trips over a 24-hour period are well below the maximum trip levels agreed upon by the University and the City of Seattle.

• The inbound morning (peak direction) trips increased by 7.9% from 1998 to 1999.
• The outbound evening (peak direction) trips increased by 3.9% from 1998 to 1999.
• The number of total trips over a 24-hour period increased by 5.9% from 1998 to 1999.

Five appendices were prepared for this report:

• Traffic Counts by the UW Transportation Office and Trafficount Inc.
• Balancing of Entering and Exiting Campus Vehicle Trips
• Campus Vehicle Parking Counts 11:00 PM to 1:00 AM
• West Campus Parking Lot Counts, West Campus Trip Generation
• Comparison of 1999 Annual Campus Traffic Count to 1999 University District Cordon Study