Traffic Data Reveals River View Cemetery as a Crucial Corridor for Portland Bicyclers and Vulnerable Road Users

Direction of Travel: The Crucial Uphill/Downhill Divide

The data highlights the cemetery's critical function as a connection for cyclists traveling uphill toward Lewis & Clark College, the Terwilliger Parkway area, and Southwest neighborhoods as well as potential recreational and training rides.

Overall, there were significantly more bicycles entering the cemetery (going uphill) versus exiting (going downhill) at a ratio of 201 to 103 bicycles ADT. This is a powerful finding, as the most challenging and dangerous alternative, S Taylors Ferry Rd, is primarily an uphill/eastbound slog with an 85th percentile speed of 44 mph (in a 35 mph zone) and high Average Daily Traffic (ADT) counts of over 6,000.1

The opposite trend was observed for vehicles and pedestrians, with more exiting (downhill) than entering, indicating that drivers see the cemetery as a viable link for downhill travel as high-speed cut-through to avoid potential congestion on Taylor’s Ferry or Macadam. This also creates more potential conflict, as daily pedestrian count is slightly higher than vehicles, at 90 vs 88 ADT, and all user activity increases during the evening commute time.

Vehicle Speed is the Primary Safety Threat

The most alarming discovery relates to speed. The speed limit within River View Cemetery is 15 mph. The data clearly shows that vehicles are routinely exceeding this limit, posing a direct threat to all other users.

• 66% of vehicles were captured moving over 15 mph (the speed limit), compared to just 15% of bicycles.

• This speed differential is magnified when traveling downhill: 74% of vehicles vs. 39% of bicycles were over 15 mph.

• Vehicles maintained a high average speed regardless of direction: 15 mph uphill vs. 17 mph downhill.

• Bicycles, by contrast, had a major directional speed difference: 7 mph uphill vs. 14 mph downhill.

This confirms that the cemetery's roads are being treated as a high-speed, non-residential street by most drivers, directly contrasting with the intended quiet nature of a cemetery and the safety needs of active transportation users. The risks are compounded by the presence of vulnerable road users and the narrow, winding nature of the roads.

The Alternative Route Crisis

The precarious nature of the cemetery access was recently thrust into the spotlight with temporary closures due to construction, prompting a familiar outcry from the community. A recent BikePortland article, "Yes, River View Cemetery is closed to cycling. Here's why," reported temporary, safety-related restrictions and the inability of the cemetery to provide prior warnings due to outside contractors and weather concerns.

Comparing Routes: RVC is the Only Safe Option

The data provided by the analysis confirms that the alternatives are significantly longer, steeper grades, and often unsafe.

*The S Macadam Ave route is listed as a "Difficult Connection." 2

The most direct alternative, S Taylors Ferry Rd, is not a designated bicycle route. As commenters on the BikePortland article noted, it is a high-speed, high-traffic environment where the only way to feel safe descending is to take the lane at a speed nearing traffic, an option only for the "strong and fearless." The fact that the 85th percentile speed on Taylors Ferry is 49 mph westbound and 44 mph eastbound—far exceeding the 35 mph posted limit—makes it a dangerous prospect for most cyclists.

The Value of Rapid, Affordable Data Collection

The data are clear. The predicament presented by the roadway data—high-speed motor vehicles, peak commuter traffic, and the ever-present threat of closure—deserves immediate and concrete action. While the discussion is often complicated by philosophical debates over private property, tax exemption, and the sanctity of cemeteries, the core issue remains: There is no safe, public, guaranteed, and direct connection for active transit and non-vehicular users between the Sellwood Bridge area and SW Portland.

The comprehensive traffic and speed data, focused on holistic roadway data–not just car-centric numbers, and collected over a six-week period, is crucial for informing stakeholders—including Lewis & Clark College, RVC, and Portland City Council District 4 representatives. This fact-based approach is vital for making decisions that ensure the safety and connectivity of the community, especially for vulnerable road users.

The reality is that city agencies often face capacity constraints. Despite Taylor’s Ferry Road being designated as a high motor vehicle collision road, the City of Portland's transportation bureau (PBOT) has been asked to deploy traffic counters in the past but has not had the capacity to do so. Furthermore, as shown by the RVC analysis, a few hours or days of counting would not have had the ability to showcase the rich data captured and presented here, especially the distinct trends between weekdays and weekends, and uphill vs. downhill speeds. The long-term trend data is essential for accurate policy decisions.

The deployment of the TrafficMonitor.ai device highlights how communities and advocates can gather the robust data they need to spur action.

Methodology

The data was collected at one point: the cemetery entrance gate near the Sellwood Bridge, using a trafficmonitor.ai device—an open-source smart city traffic monitoring solution utilizing edge machine learning object detection and Doppler radar that is built right here in PDX for citizen scientists, advocates, and engineers. Collecting this rich data—including object counts, speed, and directional travel—was accomplished quickly, affordably, with little intervention and no impact on roadway users or staff. This data collection study was estimated at less than $1,000 to implement. Comparable private counting and speed analysis on a multi-modal route often costs upwards of $29,000.

Roadway Biome Capabilities

Roadway Biome builds and utilizes the trafficmonitor.ai system that prioritizes privacy. The device uses local object detection inferencing and Doppler radar, not capturing or storing identifying visuals (no images, license plates, or faces). It only records the object class (bicycle, vehicle, pedestrian), times, speed, and direction for fully local data de-identification. This ensures ethical, granular, and holistic data collection on traffic patterns for urban planning, without compromising user identity or personal information.

Data Definitions

Object detection labels and classification:  

AI Transparency disclosure: This analysis utilized the public domain Coral SSDLite MobileDet based on the public domain COCO dataset with the following labels:

• Bicycle: combined ebikes, bikes

• Vehicle: combined cars, trucks, motorcycles

• Pedestrian: person (minus) bicycle (may include scooters and non-bicycle micro-mobility)

Glossary of terms:

• ADT, Average Daily Traffic; volume of traffic for specified object

• RVC, River View Cemetery

• Uphill and Downhill directions refer to travel into and out of the cemetery from Macadam’s, respectively (westbound and eastbound)