{"id":157,"date":"2026-08-18T07:18:03","date_gmt":"2026-08-18T07:18:03","guid":{"rendered":"https:\/\/auroraaccidentlawyer.com\/blog\/?p=157"},"modified":"2026-08-18T07:18:55","modified_gmt":"2026-08-18T07:18:55","slug":"aurora-intersection-redesign-roundabouts","status":"publish","type":"post","link":"https:\/\/auroraaccidentlawyer.com\/blog\/aurora-intersection-redesign-roundabouts\/","title":{"rendered":"Roundabouts, Flashing Arrows, and Speed Cushions: How Aurora Is Redesigning Its Most Dangerous Intersections"},"content":{"rendered":"\n

Ask most drivers whether a traffic light or a roundabout is safer, and they’ll pick the light almost every time. The data says the opposite. When Aurora swaps a signaled intersection for a roundabout, fatal crashes drop by 90 percent and injury crashes drop by 75 percent. That’s not a small tweak. That’s a different way of moving cars through a space entirely. <\/p>\n\n\n\n

Aurora, Colorado’s third-largest city, has spent the last few years quietly rebuilding its worst intersections around this idea, trading signals for circles, fixing a decades-old left-turn signal problem, and rolling out speed bumps built specifically for residential streets. Here’s what’s actually happening, and why it matters if you drive through this city on any kind of regular basis<\/a>.<\/p>\n\n\n\n

Why a Circle Beats a Straight Line<\/h2>\n\n\n\n
\"Diagram<\/figure>\n\n\n\n

Picture a normal four-way intersection with a light. Every direction a car can go, whether it’s turning left, going straight, or merging, creates a point where two cars’ paths could cross. Engineers call these conflict points. A standard signaled intersection has 32 of them. Sixteen are crossing conflicts, meaning one car cuts straight across another car’s path. Those are the ones that cause T-bones and head-on collisions. Those are the crashes that kill people.<\/p>\n\n\n\n

A roundabout gets rid of all sixteen. Cars move counter-clockwise around a center island, and there’s exactly one rule: whoever’s entering yields to whoever’s already going around. No left turn across oncoming traffic, because there’s no oncoming traffic left to cross. <\/p>\n\n\n\n

Raised islands on each approach bend the road so nobody can barrel straight through, which knocks entry speeds down to somewhere between 15 and 30 mph. What’s left is 8 conflict points instead of 32, and none of them are the head-on kind.<\/p>\n\n\n\n

\"A
Representational Image<\/figcaption><\/figure>\n\n\n\n

That speed drop does more work than it sounds like it should. A car hitting something at 45 mph carries roughly five times the force of the same car at 20 mph. So when crashes do happen at a roundabout, they tend to be low-speed sideswipes between cars moving in close to the same direction, not a T-bone at 40 mph. <\/p>\n\n\n\n

That’s the real mechanism behind the headline numbers: 90 percent fewer fatal crashes, 75 percent fewer injury crashes, 37 percent fewer collisions overall, and 40 percent fewer pedestrian crashes, according to research from the Federal Highway Administration<\/a> and the Insurance Institute for Highway Safety<\/a>.<\/p>\n\n\n\n

There’s a pedestrian upside too, and it’s easy to miss. The raised islands split a crossing into two shorter steps instead of one long walk across several lanes, so you only have to watch one direction of traffic at a time. And if you’re wondering how a delivery truck or a city bus gets through a roundabout without chewing up the landscaping, there’s a mountable curb called a truck apron ringing the center island. It lets the rear wheels of a big vehicle swing over it without the whole intersection needing to be built oversized just to fit trucks.<\/p>\n\n\n\n

Fixing the Left-Turn Signal Nobody Reads Right<\/h2>\n\n\n\n
\"Diagram<\/figure>\n\n\n\n

Not every intersection can become a roundabout. So Aurora’s also been fixing something that’s quietly caused crashes for years: the plain green ball used for left turns. A lot of drivers see solid green and read it as “go,” full stop, even when they’re turning left across oncoming traffic they’re technically supposed to yield to. That misread is a documented cause of left-turn crashes, and it’s a hard habit to talk people out of.<\/p>\n\n\n\n

The fix is called a Flashing Yellow Arrow. Four signals, four clear meanings: solid red means stop, solid yellow means the light’s about to change, a flashing yellow arrow means you can turn left but only after yielding, and a solid green arrow means the turn is fully protected with no oncoming traffic at all. The system can switch between protected-only mode during rush hour<\/a> and the more flexible flashing mode when the road’s quieter.<\/p>\n\n\n\n

Aurora’s installed these along Galena Boulevard and Indian Trail, plus the cluster of intersections where Havana Street meets 11th Avenue and Del Mar Parkway. The city also added reflectorized backplates<\/a>, strips around the signal head that stay visible even without power, so a blackout doesn’t leave an intersection completely dark. Separately, Aurora hired the engineering firm Stantec to retime close to 300 signalized intersections citywide, adjusting how long each light stays green and how the timing lines up from one signal to the next, so a line of cars actually has a shot at getting through several lights without hitting red every single time.<\/p>\n\n\n\n

The retiming also builds in priority for RTD buses, Denver’s regional transit system, at certain intersections, and adds extra crossing time for pedestrians where ADA accessibility rules require it.<\/p>\n\n\n\n

Neighborhood Streets Get Their Own Toolkit<\/h2>\n\n\n\n

Roundabouts and signal fixes handle the big intersections. For residential streets where the complaint is plain old speeding, Aurora runs something called the Neighborhood Traffic Calming Program, and it’s more selective than you might expect. The street has to be classified as local or collector, not a major arterial. It needs at least 500 vehicles a day. It has to be posted at 35 mph or under. <\/p>\n\n\n\n

Residents also have to show there’s an actual speeding problem and get a minimum number of households to sign on in support. If a street doesn’t qualify, or the project doesn’t move forward, that same location can’t reapply for three years.<\/p>\n\n\n\n

Once a street clears that bar, the city runs an initial eligibility check within about two weeks, then goes out and pulls real numbers: actual speeds, traffic volume, crash history. Staff sit down with residents, walk through what they found, and work out a design together. The project then gets ranked against every other qualifying street based on how bad the crash history is and how much community support it has.<\/p>\n\n\n\n

The devices themselves get matched to what a street actually needs. Mini-roundabouts use a flush island that a fire truck can drive straight over while everyday traffic still gets slowed down. Speed cushions are raised bumps with gaps cut for wider wheelbases, so an ambulance or fire engine can straddle them at full speed while a regular car gets forced down to 20 or 25 mph. <\/p>\n\n\n\n

Curb extensions shorten the distance pedestrians have to cross and tighten the corner so nobody’s taking a right turn at speed. And Rectangular Rapid Flashing Beacons give pedestrians a button-activated flashing light at crossings that don’t have a full signal, which noticeably improves how often drivers actually stop.<\/p>\n\n\n\n

Northwest Aurora is a decent example of all this coming together. The city landed a $1.6 million state and federal grant, kicked in its own 20 percent match, and is using the money to build curb bulb-outs at eight intersections along a stretch of road with a well-documented history of severe crashes. <\/p>\n\n\n\n

A few miles over, the US 6 and Stonebridge Drive project is pairing a new roundabout with flashing beacons and pedestrian refuge islands to serve the River Edge, Eaglebend, and Mountain Stream neighborhoods.<\/p>\n\n\n\n

The Money Side Nobody Talks About<\/h2>\n\n\n\n

There’s a financial case here too, and it’s bigger than most people would guess. Stop-and-go traffic burns more fuel than steady movement, since accelerating from a dead stop takes a lot more gas<\/a> than holding a constant speed. Research from the Transportation Research Board<\/a> and FHWA found that converting a signaled intersection into a roundabout cuts fuel use by up to 30 percent.<\/p>\n\n\n\n

\"Infographic<\/figure>\n\n\n\n

At a small single-lane roundabout, that works out to around 14,900 gallons saved a year. At a large multi-lane one, it can hit 579,000 gallons annually. The same conversions cut carbon monoxide by 29 to 32 percent, nitrogen oxides by 21 to 34 percent, carbon dioxide by 37 percent, and hydrocarbons by 42 percent.<\/p>\n\n\n\n

Maintenance tells a similar story. A traffic signal needs bulbs replaced, detector loops repaired, a controller box serviced, and it draws power around the clock. A roundabout needs some landscaping and an occasional repaint of the lane markings. That gap shows up hardest during a power outage. <\/p>\n\n\n\n

A roundabout keeps working exactly the way it always does. A signal either goes dark or drops into flashing mode, which is precisely the moment drivers most need clear right-of-way rules and have the least idea what they are.<\/p>\n\n\n\n

What This Means the Next Time You’re Driving Through Aurora<\/h2>\n\n\n\n

None of this is abstract policy sitting in a planning binder somewhere. It changes how you should actually handle specific intersections around the city. At a roundabout, yield to whatever’s already circulating and don’t stop unless you truly have to. At a flashing yellow arrow, treat it as permission to turn only once you’ve confirmed oncoming traffic is clear, not as a green light. Expect to see more of both as Aurora keeps working through its Connecting Aurora plan<\/a>. The city isn’t chasing a trend here. It’s converting the specific spots where its own crash data shows people keep getting hurt, one intersection at a time.<\/p>\n","protected":false},"excerpt":{"rendered":"

Ask most drivers whether a traffic light or a roundabout is safer, and they’ll pick the light almost every time. The data says the opposite. When Aurora swaps a signaled intersection for a roundabout, fatal crashes drop by 90 percent and injury crashes drop by 75 percent. That’s not a small tweak. That’s a different […]<\/p>\n","protected":false},"author":1,"featured_media":160,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"advanced_seo_description":"Aurora is trading traffic lights for roundabouts and flashing arrows, cutting fatal crashes by 90%. Here is what drivers need to know.","jetpack_seo_html_title":"Why Aurora Is Swapping Traffic Lights for Roundabouts Fast","jetpack_seo_noindex":false,"jetpack_seo_schema_type":"article","_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[73],"tags":[69,144,16,143,142],"class_list":["post-157","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-local-infrastructure-civic","tag-aurora-road-safety","tag-car-accident-prevention","tag-dangerous-intersections","tag-roundabouts","tag-traffic-calming"],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":8}},"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/i0.wp.com\/auroraaccidentlawyer.com\/blog\/wp-content\/uploads\/2026\/08\/Aurora-Colorado-roundabout-aerial-view-traffic-safety-scaled.jpg?fit=2560%2C1429&ssl=1","_links":{"self":[{"href":"https:\/\/auroraaccidentlawyer.com\/blog\/wp-json\/wp\/v2\/posts\/157","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/auroraaccidentlawyer.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/auroraaccidentlawyer.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/auroraaccidentlawyer.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/auroraaccidentlawyer.com\/blog\/wp-json\/wp\/v2\/comments?post=157"}],"version-history":[{"count":5,"href":"https:\/\/auroraaccidentlawyer.com\/blog\/wp-json\/wp\/v2\/posts\/157\/revisions"}],"predecessor-version":[{"id":167,"href":"https:\/\/auroraaccidentlawyer.com\/blog\/wp-json\/wp\/v2\/posts\/157\/revisions\/167"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/auroraaccidentlawyer.com\/blog\/wp-json\/wp\/v2\/media\/160"}],"wp:attachment":[{"href":"https:\/\/auroraaccidentlawyer.com\/blog\/wp-json\/wp\/v2\/media?parent=157"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/auroraaccidentlawyer.com\/blog\/wp-json\/wp\/v2\/categories?post=157"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/auroraaccidentlawyer.com\/blog\/wp-json\/wp\/v2\/tags?post=157"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}