2022 SANDAG Commercial Vehicle Survey 

About the SANDAG Commercial Vehicle Survey

This page summarizes findings from the Commercial Vehicle Survey (CVS) conducted in the spring 2022 through winter 2022 in San Diego County by ETC Institute in coordination with RSG on behalf of SANDAG. Focusing on the movement of commercial vehicles rather than passengers, the CVS captured arrival and departure times, cargo details (load and type), trip purpose, and information about vehicles’ origins and destinations from a statistically valid sample of establishments in the region. Besides providing a comprehensive picture of commercial vehicle operations, the data will be applied by SANDAG and its partners to develop quality model forecasts to help prioritize infrastructure investments that will enhance the overall quality of life and economic competitiveness of the region. 
The CVS consisted of three parts:

An establishment survey that was designed to understand the number and types of commercial vehicles that are operated by a diverse sample of business establishments in the region.
A passive GPS travel diary that collected GPS data for the trips made by a subset of the vehicles operated by establishment survey participants. The travel diary was primarily administered to drivers using a mobile app that enabled efficient and accurate collection of vehicle movements while significantly reducing survey response burden. 
A GPS travel diary of Transportation Network Company (TNC) drivers in the region. In contrast to traditional commercial vehicles, TNCs typically offer on-demand business-to-consumer delivery services prearranged over an online app. Because this group represents a special population distinct from regular commercial vehicle travel, it is presented separately from traditional commercial vehicles.

The Survey at a Glance

The establishment survey was conducted to explore the usage of commercial vehicles among businesses, and out of the 28,000 commercial establishments in the SANDAG region, 2,697 responded, revealing that 39% own or lease commercial vehicles for business purposes.
A total of 1,751 vehicles completed the comprehensive 24-hour CVS diary and 411 TNC drivers participated in the research. The data collection efforts produced a rich origin-destination dataset of 15,940 trips, encompassing both commercial and TNC vehicles.

What kind of data did the survey collect from vehicles and drivers?

The CVS employed a travel diary methodology over a smartphone-based app to record each participating vehicle's movements for 24 hours and asked drivers to provide detailed information about all their stops. The travel diary methods allow the data to be grouped and analyzed by stops, trips, and tours - a necessary level of detail to enable subsequent modeling and forecasting tasks.

A trip connects two stops, while a tour is a chain of trips that usually, but not always, starts and ends at a base location. An example of a tour with its constituent stops and trips is shown in the graphic below.  

Comprehensive Trip and Tour Data

The survey asked drivers for detailed information describing vehicle movements and trip-making patterns.  Commercial vehicles, on average, made 4 stops on each tour, while TNC drivers made more than 10 stops. 

Travel Diary Results

The section presents the results obtained from the travel diary component of the CVS. Diaries were distributed to drivers through a mobile app and participants were selected from eligible establishments that took part in the Establishment section of the survey. Trip and stop data were expanded using County Business Pattern (CBP) and California Economic Development Department (CA EDD) data to represent the estimated total number of daily commercial vehicle trips in San Diego County.
Many statistics in the travel diary section are presented by industry type, as this constitutes the primary variable by which shipping characteristics vary. This distinction is crucial to validate and include in the reporting process.

Trip/Stop Characteristics

10,687 trips from all vehicle types were collected by the commercial vehicle travel diary survey. Each trip included information about stop location (e.g., address, coordinates), place type, arrival and departure times, and specific purpose.

Vehicle Types

For the analysis of trip and stop data, vehicles were grouped into distinct categories based on their size. 

Trip Distance and Travel Time

Light vehicles and medium trucks share similar trip characteristics, while heavy-truck journeys stand out for being both longer in distance and duration.

VMT and VHT

Vehicle miles traveled (VMT) and vehicle hours traveled (VHT) varied by vehicle type. While heavy vehicles made up only 12% of all trips in the region, they accounted for 19% of VMT and 17% of VHT.

Stop Purpose

The travel diary asked respondents to record the specific activities performed at each stop. These responses were grouped into four distinct stop purpose categories, as outlined on the right.

Average Trip Duration

Heavy trucks have longer trips compared to medium and light vehicles. On average, the longest trips were conducted to pick up or drop off goods.

Average Stop Duration

Light vehicles have longer stop times on service-related stops compared to other types of vehicles and stop purposes. 

Trips by Origin-Destination Segment

All trips were analyzed by their origin and destination locations:
  • Internal-Internal:  Trips that started and ended in San Diego County (96% of all trips).
  • Internal-External: Trips that started in San Diego County and ended outside of San Diego County (1% of all trips).
  • External-Internal: Trips that started outside of San Diego County and ended inside San Diego County (1% of all trips).
  • External to Region: Trips that started and ended outside of San Diego County (2% of all trips).

Arrival Time Period

Irrespective of vehicle type, most trips were made in the middle of the day, with a smaller concentration of stops occurring in the AM Peak period. 

TOUR CHARACTERISTICS

Tours typically included multiple trips that start and end at a base location. Grouping each driver's trips into tours is an essential data format for the next phase of this research which includes forecasting future commercial vehicle activities throughout the region.  
The figure below summarizes the survey's tour data including average tour distance, time, and number of stops. 

Tour Distance and Time

Light vehicles and medium trucks exhibit comparable tour characteristics, with heavy-truck tours distinguishing themselves through their notably greater distance and duration.
Each stop within a tour included a purpose/activity; this information can be used to characterize overall tour purpose based on the combination of stop purposes. Tours were allocated to four tour purpose types:
  • Goods Tours: These are tours that have one or more goods stops, no service stops, and may or may not include other stop types (17% of all tours). 
  • Service Tours: These are tours that have one or more service stops, no goods stops, and may or may not include other stop types (62% of all tours). 
  • Goods and Service Tours: These are tours that have both goods and service stops, and may or may not include other stop types (4% of all tours). 
  • Other Tours. These are tours that have no goods or service stops, only other stops such as driver needs or vehicle refueling (17% of all tours). 

Tour Purpose

Heavy vehicles had the longest tour times (395 minutes) in the combined Goods and Service type tours. Light vehicles tended to have the longest Service type tours (245 minutes), whereas medium vehicles had the shortest (227 minutes). This excluded travel starting and ending outside San Diego. Tour time included time spent traveling, as well as at stops.

Number of Stops per Tour

Data on the number of stops per tour, categorized by vehicle type, was gathered. Tours with more than 16 stops were grouped into the 16-stop category. As vehicle size increases, the distribution is more skewed toward single-stop tours. Approximately 40% of tours made by heavy vehicles consist of just one stop.

Establishment Survey Results

Of the approximately 28,000 commercial establishments in the SANDAG region, 54% received an invitation to participate in the survey. During the administration, 2,697 businesses completed the establishment survey. Of those, 467 businesses reported in the travel dairy that they had one or more vehicles they owned or operated. Sample targets were established based on company size and by the North American Industry Classification System (NAICS) type. 

Sampling and Participation 

The main objective of the establishment survey was to gather a varied sample of the region's establishments, serving as a pool from which drivers could be recruited to take part in the vehicle survey.

The figures below illustrate the alignment between participation in the establishment survey and the sample universe of San Diego business establishments defined by industry type and number of employees (firm size). 

Participation by Establishment Type

The overall participation rate across industry types closely mirrored the distribution of industries in the San Diego region. The Info/Finance/Insurance/Real Estate/Professional Services (Info/FIRE/Professional Services) sector, which comprised 28% of all establishments, emerged as the largest industry type and exhibited the highest survey participation, accounting for 16% of all completed establishment surveys.

Participation by Workforce Distribution

The distribution of respondents employed within each industry group closely aligned with the overall workforce distribution of San Diego region. The second-largest employer in the San Diego region was the Leisure/Accommodation and Food Services sector, which comprised 15% of the workforce and accounted for 18% of all establishment survey employees.

Establishment Locations

Participating establishments were widely distributed across the San Diego Region. Higher concentrations of completed surveys were collected from the North City sub-region, while the lowest proportion of surveys were collected from the East County sub-region. 

Ownership and Use of Commercial Vehicles

Establishments reported their ownership and use of vehicles:

  • 39% of establishments owned or leased vehicles (from cars to trucks or other large vehicles) that are used for business purposes.
  • Employees at 23% of the establishments used their personal vehicles for business purposes.
  • 23% of the establishments used at least one non-owned or leased vehicle for commercial purposes.

The figure below shows how many vehicles of each type were available, on average, to those establishments that used commercial vehicles. Larger vehicles are almost always owned or leased by the business, while smaller vehicles, such as cars and single-unit trucks (SUTs), are often owned by others, such as employees.

Full Report

This dashboard summarized key findings from the SANDAG Commercial Vehicle Survey Report. For more in-depth information, please refer to the full report available [here].