a practical, cost-effective path toward making our streets more intelligent

By Julian Stromer, Jan 11, 2025

Our existing sidewalk and road infrastructure are built on ancient technology: concrete and asphalt. When cities add intelligence to our streets, the technology has to be installed over, under and around these obstacles. Instead, we should be installing new tech inside the infrastructure.

Further, each new technological improvement ends up being implemented independently, which is inefficient, expensive, hard to maintain, and nearly impossible to upgrade.

With the evolving needs for our city sidewalks and roads and the opportunities offered by the availability of new sensing and data communication technologies, we can make our streets better serve our modern needs, preparing us for the challenges of climate change and safely accommodating a wide diversity of able and challenged pedestrians and vehicles, including bikes and scooters, cars and trucks, delivery and public transport vehicles.

Defining problems with city street usability

Cities like New York have been working hard to make their streets safer and more accessible for everyone. They have improved the accessibility ramps at street corners. They have added many miles of bike lanes, and have pushed parking spaces away from the curbs to give added protection to bike lane users. They have reduced the number of lanes on large streets to better control the speed and flow of vehicles, and have pushed sidewalks further into crosswalks to make pedestrian crossing safer. They have removed parking spaces near intersections to improve visibility. They have reduced speed limits, and have installed cameras that automatically ticket speed violators. They have closed roads to create safer, more walkable neighborhoods, and have turned some of these roads into plazas, with seating and planters. Just recently, they have begun adding congestion-pricing zones, where vehicles are charged extra tolls to drive into the busiest areas of the city, in order to discourage car use, and to raise money to improve public transportation.

All of these improvements are steps in the right direction, but the city’s Department of Transportation (DOT) is constantly looking for ways to better manage the complicated relationship between pedestrians, personal vehicles, commercial vehicles, cabs and ride-share vehicles, rental vehicles, emergency service vehicles, bikes, e-bikes, scooters and other micro-mobility vehicles, among the many others using the roads.

The city has installed thousands of cameras, on poles and on city busses, which can intelligently identify vehicles, provide live traffic monitoring, charge motorists fines for some violations, and do other helpful tasks. However, the cameras have many limitations, starting with how costly they are to install and maintain, how easily they can be outsmarted with tricks as simple as wiping mud on a license plate, and how invasive and “big brother” they seem, looking down on everyone.

Street design, new laws, and the use of cameras can all play a part in improving our city’s streets, but achieving the level of efficiency that the DOT says it wants to achieve will require low-cost technology being installed for nearly every inch of our sidewalks, roads, and the crosswalks and curbs between them.

Researching possible solutions

I set out to understand the wide range of needs and opportunities for improving the urban street experience for all of its users. Our sidewalks and streets can do so much to improve the lives of their users beyond the basic transport functions they currently offer.

I took to the streets to try to note all of the different ways in which our sidewalks and streets are used by different communities throughout New York City. I found almost countless ways where adding technology would make all users of the sidewalks and streets safer and more efficient.

In fact, there are so many ways that low-cost technology could improve the usability of our streets that I realized two important basics: whatever I built would need to be easily changed so that it could adapt to changing needs and new ideas, and it would need to somehow be installable a bit at a time, and without causing much disruption to a very busy city.

I quickly realized that intelligent sidewalks and roads would need a network to run through them. It seemed impractical to consider tearing up the sidewalks or roads to install this network, but then I realized that the curbs between the sidewalks and the streets were much like a spine that could carry the many services that would be needed to make our city streets smarter. I was inspired when I saw city workers installing a prefabricated street curb into a gap between the sidewalk and the roadway using a backhoe loader to drop it into place.

I did some research and found that while the idea of making our curbs better designed and capable of some basic smart features has been lightly touched on, there has been no successful design, patent, or implementation of a genuinely technology-driven street curb.

Configureable curb versions

In addition to making the internal electronics and software modular, the curbs will have secure mounting holes for parking meters, EV charging jacks, bike racks, security bollards, pedestrian seating and other peripheral hardware to be mounted into. These mounting points will be able to carry electricity and data connections into the mounted hardware to provide added intelligence and features to these devices, as well as to make the services each provides into billable services.

Potential capabilities and features

Based on my research into the goals the DOT , Emergency Services, and other city agencies wish to see implemented, the different projects that have been implemented on our streets in the past, and the needs that I saw in my own observations, I compiled a list of capabilities and features that could potentially be integrated into my modular curb designs. While it was not possible to integrate all of these capabilities into my first prototype, I was able to implement a few, in order to test and demonstrate the practicality of the basic design.

• capabilities built into prototype

Requirements: creating a modular design

Once I had listed all of the capabilities and functions I wanted my intelligent curbs to perform, I began to see how making them modular and customizable would be the best way to implement the many different solutions I wanted curbs to be able to offer. In this way, each section of street curb could be equipped and programmed to recognize and perform its unique role: as a bus stop curb, a bike rack curb, a vehicle charging station, and so on.

Requirements: selecting a suitable material

One of the first, and most important decisions was to select a replacement material for the standard concrete and stone usually used for making street curbs. Already, there are parts of the street infrastructure that are being made from extremely strong plastics, such as the high-visibility yellow handicap ramps located at street corners, and the heavy temporary barriers used to close lanes and to redirect traffic along highways during construction.

Environmental considerations: recycled plastic versus concrete

It may seem environmentally irresponsible to use plastic to replace concrete in the making of street curbs. However, this is not really the case. The high strength plastic known as HDPE (High-Density Polyethylene), can be manufactured from recycled bottles and similar plastic waste, and with the enormous volume of material that would be needed to install curbs throughout our largest cities, this would give purpose to an overloaded and underused waste stream.

In contrast, the manufacture of concrete is responsible for between 4 and 8% of global carbon dioxide (CO2) emissions due to the combustion of fossil fuels and from the chemical reaction of limestone in the process, while also being one of the largest drains on fresh water resources.

Strength & Resilience

HDPE, in the right thickness, can easily withstand the weights of cars and trucks. In fact, it is known precisely for its strength, durability, and chemical and impact resistance. Additionally, it is extremely resistant to the sun’s UV rays, and it is essentially waterproof. It is heat resistant, low-maintenance, resistant to infestation, fungal growth and rot. While HDPE is not impervious to wear, neither is concrete, which breaks down over relatively short periods, due to the cycles of freeze and thaw experienced by street curbs.

Requirements: making street curbs ‘communicate’

It might seem logical to connect all of the curbs together with wire for network communication, but there are many problems with this. First, there’s no easy way to continue wire across roads. Second, a break anywhere along the wires would take entire sections offline, and it would be hard to locate and gain access to these wires. Instead, a better solution is to have the curbs communicate wirelessly. On each few blocks, the nearby curbs can all report to a central hub that would then forward messages on to a central station.

As most people experience in their own homes, traditional WiFi has a hard time reaching from one room to the next, so this isn’t ideal for a solution that requires communication over one or two mile distances. We’ve all gotten used to using cellular wifi services, which can reach literally anywhere, as long as there’s a cell tower available within a block or two. However, the cell towers are owned by private companies that charge for carrying data. Also, when the electricity goes out, the cell towers go out, too.

There is a type of long range WiFi that is extremely inexpensive, works for miles, and doesn’t need the help of private companies. In fact, even the federal government doesn’t bother to regulate or license it. This technology is called LoRa, an abbreviation for Long Range.

What is LoRa?

LoRa is a radio device designed for use in low power, low bit rate IoT (Internet of Things) and similar devices. LoRa uses sub-gigahertz radio frequency bands (902–928 MHz in North America) that do not require a license. LoRa devices achieve data rates between 0.3 kbit/s and 27 kbit/s, so not nearly quick enough for sending data-rich content like pictures or video, but perfect for sending bits of important data, like the value being read by a sensor. Most amazingly, these radios, which are about the size of a quarter, can send messages for a distance of around twelve miles!

Requirements: securing curbs from hacking

Security of network equipment takes place at many different layers.

The physical layer

First, we need to keep the equipment safe from physical intrusion. At this layer, we need to protect the curb from being tampered with. I have installed a sensor in my circuit that instantly knows when a cover has been opened. When it detects this, the curb alerts the central station, and also takes itself off-line, so that any access can be reviewed and authorized before the unit is permitted to rejoin the network.

The hardware layer

The hardware layer is the CPU, the network devices and other electronics installed inside of the curb. The curb’s software records all changes to it’s hardware, such as when a sensor wire is disconnected, by immediately reporting these changes to the central station as they happen, and alerting the appropriate authorities when these changes are being made without proper authorization.

Next, the LoRa radios in each curb have unique identifying numbers that can not easily be duplicated. This lets us know when an unauthorized radio has attempted to join the network, or when a radio is trying to impersonate being a radio that is authorized.

The network layer

The LoRa radios are capable of point-to-point encryption, so that any data pulled from the air by a hacker will not be readable.

Only as secure as needed

Finally, the data from any single curb is not so sensitive that we need to over-worry about keeping the information secure. In fact, a lot of the information being collected would probably be the most beneficial if it were being openly shared with residents and visitors.

Sources

LoRa Radio

YouTube: Data Slayer, You’ve Never Seen WiFi Like This

Esclabs.in: Edison Science Corner, How to interface LoRa module with Arduino | Reyax RYLR998

YouTube: Mario's Ideas, Arduino meets RYLR998: A Comprehensive Guide to LoRa Module Integration

thethingsnetwork.org: Duty Cycle

SunfireTesting.com: Tim Payne, LoRa FCC Certification Guide

Water Sensor

Electronicsforu.com: Fully Non-invasive Liquid Level Detection

Force Sensitive Resistor

Sparkfun.com: jimblom and bboyho, Force Sensitive Resistor Hookup Guide

Ambient Light Sensor

AllDatasheet.com: Everlight Ambient Light Sensor Datasheet

DFRobot.com: Gravity Analog Ambient Light Sensor

DFRobot.com: Analog Ambient Light Sensor

NYC Department of Transportation Planning

NYC.gov: NYC SmartCurbs Project, NYC DOT Curb Management Action Plan.pdf