Types of Transit Infrastructure
Types of Transit Infrastructure
Chicagoans take hundreds of millions of CTA bus rides each year. The reliability and convenience of transit service hinges on the safety and efficiency of roadways that CDOT builds and maintains. Forward-thinking designs that prioritize bus transit are a core focus for Complete Streets. Examples of these emerging designs are included on the page below.
Bus Bulbs & Bus Boarding Islands
Bus boarding islands are exclusive spaces for people awaiting, boarding, and alighting public buses. Unlike a traditional bus stop, a boarding island is installed in between a vehicle travel lane on one side and a protected bikeway on the other side, with a short crosswalk for bus riders to cross the bikeway for sidewalk access.
Bus Bulb
Also called a bus stop bump out or curb extension, this tool extends the sidewalk or boarding area closer to the travel lane, typically aligning with an existing parking lane. This allows buses to make service stops from within the travel lane, reducing stop time and delays from merging in and out of traffic. Bus bulbs create a larger space for people to wait for the bus, and for operators to deploy accessible ramps when needed. They also reduce crossing distance to and from the opposite side of the street, improving access and safety.
Boarding Island
Raised concrete islands are placed between vehicle lane(s) on one side and bike lane(s) on the other to help to minimize conflicts between buses and cyclists at service stops. This improves safety and comfort with continuous separation, unlike older designs that require buses to cross over bike lanes to pick up and drop off passengers. The bike lane typically remains at street level, but where there is not sufficient width for a fully separated accessible island, the bike lane may be raised and connected at sidewalk level—a type of “hybrid” bus bulb and boarding island.
Bus Lanes
Bus lanes are travel lanes dedicated to transit buses, with various restrictions on use by other vehicles. Signs and pavement markings designate various bus lane restrictions; some prohibit non-transit vehicles 24 hours per day, while others only restrict use during certain times, such as rush hour. At intersections, some bus lanes may be shared by turning vehicles. People driving should observe signs and pavement markings to ensure compliance. Bus lanes may vary in length.
See examples of various bus lanes below:
Bus Lane Along a Corridor
This is a travel lane dedicated to bus use, with restrictions on use by other vehicles. It can be a short or long length of a street and can be reserved for buses at all times of day or just during specified times, such as rush hour.
Bus Lane at Identified Trouble Spots
Bus lanes can be designated at specific locations identified by CTA and CDOT as a source of significant delays. These lanes can improve operations at a particularly congested segment.
Bus-Bike Lane
This is similar to a bus lane, but is shared with people biking. Similar to bus lanes, they can be in effect at all times or just during specified times of the day or week, such as rush hour. Generally, bus-bike lanes use the curbside lane.
Smart Streets
The Smart Streets Pilot Program ("Smart Streets") is an enforcement program that aims to improve traffic safety, enhance protections for pedestrians and bicyclists, and speed up public transit. The City will use existing infrastructure and new technology to encourage safe driver behavior and compliance. The Smart Streets program includes enforcement of bus and bike lane violations in a pilot area.
Accessibility Upgrades
Accessibility enhancements at bus stop locations improve the transit experience for all users, and help make the bus a more viable option for community members using assistive devices. CDOT is installing the following types of accessibility improvements in partnership with CTA:
Paved Bus Boarding Areas
Installing pavement within a grass parkway allows bus ramps to deploy properly and creates an accessible pathway from the sidewalk to the bus stop. This makes boarding and alighting safer and more practical for all transit riders.
Bus Stop Pads
Concrete pads, installed in the roadway adjacent to the curbside bus stops, can better withstand the weight of buses compared to asphalt. Over time this prevents grooves and bumps in the pavement, which can impact bus operations and rider access from the curb.
Traffic Signal Technologies
CDOT CTA are investing in emerging traffic management technologies that optimize bus movements.
Transit Signal Prioritization systems receive wireless signals from buses when they run behind schedule. The system may extend a green phase at a traffic light to let the bus proceed and get back on schedule.
Signal timing optimization helps ensure that streets with major bus routes get the appropriate timing at traffic signal and keep traffic flowing. This helps to maintain travel time on key transitways at peak hours.
Queue Jumps are traffic signals exclusively for buses. They are placed adjacent to other traffic signals and light up as a white vertical bar. By activating 3-5 seconds before the green phase, they give buses a head start before the rest of traffic
Bus Stop Optimization
Far Side Bus Stops
At intersections with traffic signals, bus stops located on the far side of the intersection can reduce delay because they allow buses to go through an intersection at a green light before stopping to pick up/drop off passengers. Additionally, being far side increases safety for all road users, especially pedestrians, as it prevents vehicles from illegally turning right in front of a stopped bus.