The Importance of Bridges in Bicycle and Pedestrian Networks

Currently, both the 15th Street bridge and the approach to the 20th Street Bridge between Highlands and Downtown Denver on the Highlands side are under construction. Both reconstruction efforts are part of CDOT’s continued work on I-25 which is being widened through this section of Downtown Denver to provide more capacity for automobiles. The reconstructed bridges will result in an attractive pedestrian walkway and better bicycle facilities along Central Street in the Highlands overlooking the highway. However, lacking from both these projects are significant improvements for bicycle access across the bridges. Details on the CDOT project can be found here.

Part of the reasoning for the lack of improvements is that people on bicycles should be using the series of bridges along 16th Street to access Downtown. This reasoning misses a key point. Bridges, by their nature, are pinch points that must accomodate multiple modes of transportation because all users have no choice but to funnel onto the bridge to cross what ever obstacle the bridge is crossing, be it a river, highway or railroad tracks.

The red x’s on the map above show problematic spots for bicycle access between Highlands and Downtown Denver  including the narrow bridge at 15th Street, the on-ramp and off-ramps of I-25 at 20th Street and the Millennium Bridge, which lacks bicycle ramp access.

Photo source:

The multi-use Highland Bridge works well for crossing the highway, but because the corresponding link into downtown, the Millennium bridge, lacks a ramp, it’s impractical for people on bicycle to use 16th the entire way between Highlands and LoDo. This situation, therefore, funnels people on bicycles onto 15th Street or 20th Street, both of which are problematic for entering and exiting Downtown because of roadway designs that did not take into account bicycle access. Now, as major work is done to both bridges, CDOT and the City of Denver are missing a huge opportunity to begin the process of correcting existing poor designs. The result will be the same mix of bikes and pedestrians on the crowded multi-use Highland Bridge while only the most ardent cyclist warriors will feel secure taking the most direct route into Downtown on 15th or 20th. If the city is going to reduce the conflict between people walking, people bicycling, and people in automobiles while growing the number of people commuting on bicycles, then they will need to start building more separated on-street facilities for bicycle use. These types of facilities have been shown to increase safety for all types of users: bikes, peds and automobiles.

The city’s failure to appropriately address bicycle access on 15th Street and 20th Street into the Highlands is unfortunate, but at least it can be said that these projects were designed prior to the city’s and state’s new commitment to multi-modal transportation. Denver, however, is full of bridges, and the city should not miss another opportunity to ensure that future bridge construction and reconstruction is done with a true commitment to multi-modal access. Of particular note in this regard is the W. 23rd Avenue bridge going into Jefferson Park, which may be due for reconstruction in the not too distant future, the W. 38th Avenue underpass, which is a frightening ride for even the most advanced cyclist, and the Colorado Station bridge pictured below, which, if built as currently designed, will provide much needed north/south access across I-25 for people walking and biking east of Colorado Boulevard. As of this writing, Denver Public Works is considering the final design for this bridge. Bike Denver and the Mayor’s Bicycle Advisory Committee have both taken the position that the currently approved design of the bridge, with ramp access for people on bicycles, is the best design for the Colorado Station bridge. Hopefully, Denver Public Works will move forward with the current multi-modal design of this important north/south connecting bridge.

Conceptual drawing of Colorado Station Bridge. Source: Denver Public Works:

By | 2012-07-12T20:04:20+00:00 July 12, 2012|Categories: Bicycles, Infrastructure|16 Comments


  1. Adam July 12, 2012 at 9:36 pm

    Excellent points. I live in Lower highland and would LOVE a straight shot on my bike into downtown on 16th, however I typically have to transfer on the little raven and take it to 15th, and then I take the pedestrian walkway under the railroad tracks to avoid the cars going 45 miles per hour. Once there, it is difficult to make your way back on to 15th, so it’s sidwealks until wazee, and I’ll go no wazee and around to 14th to get to civic center.

    20th is not as problematic, except for the elevation changes, as the sidewalks there are actually designated bike lanes.

    • Chris July 15, 2012 at 2:55 pm

      Actually, I think the sidewalk on 15th is also a designated bike lane, it’s just not quite wide enough for anyone to be able to haul butt.

  2. Scott July 13, 2012 at 8:19 am

    The actual bridge part of 20th isn’t too bad (as long as you stay on the sidewalk), it’s the part where it hits that intersection on the Highlands side where it gets tricky. There are a lot of streets coming together, the sidewalk on the south side just abruptly ends, and it’s not clear where you’re supposed to go, or how you’re supposed to get there.

  3. chachafish July 13, 2012 at 8:57 am

    Excellent article. Speaking of bridges, on the other side of 20th Street, the Prospect Neighborhood is completely hemmed in by 20th, 23rd and railroad tracks. The neighborhood has no access to the river walk/bike path. A bridge here to the river would be brilliant.

  4. Sarah July 13, 2012 at 8:57 am

    I am a resident on the north side of the Colorado Center bridge. We have been hoping for this for a few years. It is a vital connection in the pedestrian and bicycle network which will provide a safe crossing at I-25/Colorado Blvd/Evans Ave. There have been a few neighbors who have been very vocal in opposition. They obviously have never tried walking or bicycling at these intersections.

  5. Dave July 13, 2012 at 12:50 pm

    Thank you for bringing this up. Anybody who sees all the bikes locked up along platte street on a friday night knows how important bicycle access is for businesses and residents where parking is so limited. As Adam points out, currently there is no convenient way to get from lower highlands/ platte street to the cherry creek trail/ confluence park without riding on 15th street. Cars speed scary fast along this stretch, a road diet with protected bike lanes would make for much safer conditions.

  6. Jason July 13, 2012 at 2:04 pm

    Ahh, finally a bicycle post. I think that you are exactly right. As the Highlands and Central Platte Valley continue to densify these problems will only be exacerbated. Many people complain about parking in the LoHi area and until there are easy links many people will drive instead of bike 🙁 and bicycles and cars will continue to have conflicts.

  7. Kevin Dickson July 14, 2012 at 12:49 am

    For those of us in the south end of town, Platt Park, Wash Park, Overland, etc., there are planned bridges at Jewell and Iliff. They will be great, but they aren’t happening fast enough!

    • Dave July 14, 2012 at 6:31 am

      Also a pedestrian bridge at bayaud over the highway and tracks to the platte river trail is part of the valley EIS but i’m sure that is years away.

  8. Troy July 14, 2012 at 5:53 am

    Thanks for the bicyclying focused post and for highlighting these areas. The bicycling issues in the CPV go both ways. What I mean is that its also a significant issue for those of East of the CPV as well. There is no graded crossing / ramp between 15 th and 20 th where we can traverse the main rail line with out dismounting. If your loaded with cargo you cant huff it over the Millennium bridge. Who wants to cram into its ( or the other one a few blocks North) elevator with a bike? I don’t. In order to take cycling to the next level these issues need to be addressed.

  9. Chris July 15, 2012 at 2:58 pm

    When you say, above, that the Millennium Bridge lacks bike access, I’m guessing you mean that the bridge can’t be ridden over on a bicycle. In the for what it’s worth, category, the bridge is designed with tire wells on the steps in order for riders to be able to push their bikes up and down the steps. Not the same as just riding over, or course, but still pretty easy to do.

    The real impediment that I’ve always seen is the 16th Street Mall itself. I really do believe a full bike lane-thingy should be built on 16th. It would be incredibly popular.

    • Troy July 21, 2012 at 12:39 pm

      Yes, being able to ride over the bridge without walking your bike is what I’m talking about. Sure I’ve used the bike guides as I’ve walked over the bridge but that’s very difficult if your bike is loaded with cargo and impossible if you have a Dutch/Danish style cargo bike. Those bike guides are thoughtful and useful but not ideal like a ramp would be.

  10. Zach July 17, 2012 at 9:42 am

    This is an excellent post, and I agree with your assessment–it is a shame that the city is missing the opportunity to do something about bike access between LoHi/Highlands and Downtown.

    From what I can tell, I’m one of the few that regularly commutes via 32nd Ave/20th St. to downtown. As Chris mentioned above, the biggest issue is the transition from the designated bike paths on 20th St. to the pedestrian crossings at I-25 and access to the neighborhood from there. Riding on the designated bike sidewalk on the south side of 20th St, the sidewalk abruptly ends on the other side of the south-bound I-25 on-ramp. You are either expected to cross 20th, and then Osage; ride on the weed-infested shoulder next to the currently fenced off space in between the on-ramp and Central, or fight on-coming traffic coming blindly around the curve from Central St. and dart across several lanes of traffic. Considering this is part of a designated bike route (D-4), this is a terrible and dangerous set-up (my experience is that cars fly through these intersections, especially in making right turns on red onto and off of the on- and off-ramps).

    At a minimum, it would be great to see them extend the sidewalk around the curve on Central St. to a designated pedestrian crossing near the new Prost Brewing Company that would connect to the pathway that cuts through Highland Gateway Park to 32nd Avenue and the neighborhood.

    Not to mention that the city still needs to address adequate bike routes through downtown–especially on the numbered streets running from northwest to southeast. Other than 14th St there are no bike lanes to move in that direction without facing significant traffic. The bike lanes on 18th St are a great way to move in the opposite direction, and it would great to see them make 19th St a complement to 19th in the other direction.

    • Ken Schroeppel July 17, 2012 at 10:29 am

      Zach, fortunately, the situation at 20th & I-25 will be fully resolved with the completion of the Central Street Promenade project currently under construction by CDOT along with the highway widening and the rebuilding of 15th Street. From where the sidewalk ends on the south side of the 20th Street bridge over I-25, a new 10-foot concrete multi-use path will continue past the southbound on-ramp and then angle south through that little park area (which will be fully re-landscaped once it is no longer being used for construction staging) and then joining up along the east side of Central Street all the way to 15th Street.

  11. Will July 25, 2012 at 12:05 pm

    Are the finals plans for the 15th street bridge in place? It would be so very frustrating if the 15th street bridge is completed without any bike lanes (not just sharrows).

    According to the city site, there is still a plan–albeit vague– to implement a much needed bike lane on 15th street through Lodo to the CPV. If this happens but the lane is not continued over the bridge, it will cause another work around by way of having to take platte st to the highland bridge, which isn’t wide enough to accommodate both peds and bikers safely, imo.

    Are bike orgs ie bike Denver, the mayors bike council, and bike Colorado meeting with the city planners and encouraging them to put bike lakes on 15th? If not, we should make this issue known.

    Another possible and something that I think should happen regardless is bikes allowed on 16th street (the actual street where the mall ride goes). It would be free to implement and safe with a few easy rules eg no passing busses, stopping at stop lights. This in addition to building and actual bikeable ramp at millennium bridge would provide another avenue for cyclists, be it commuters or the increasing number of folks who bike/cruise to eat shop drink between lohi/CPV/Lodo.

    Some other mindless rants about cycling in Denver:
    -so frustrating to see all that money spent to revamp Tennyson result in no bike lanes.
    -32nd street all the way from tejon to Lowell should have a bike lane. This would be great for business, commuters, and the many fitness cyclists using 32nd as a way to get to golden and beyond.
    -somehow clean up/organize the clusterF of bikeable trails in the confluence park area ie the area to the easy of commons park west apartments, down towards REi and confluence park.
    -more bike lanes in Lodo, mid-do, and up-do (yep, I said it, haha. ) Sharrows don’t count.
    -we need a better “neighborhoody” name for the CPV area; east of 25, north of speer, south of 20th and west of the tracks that millenium bridge to over. “Commons Park? Platte Commons? I guess I would have to have a catchy two syllable nickname like Lodo, lohi, rino, etc. Maybe PlaDo (platte-downtown) haha.

    Anyways, love to story about bikes and Denver and would love to see more of them. Keep up the good work Ken!

  12. Jeff August 11, 2012 at 9:05 pm

    23rd Ave bridge is tough for a cyclist. As you ride east down to the bridge there is a “bike lane” east of Federal. More of a faux bike lane but it gets a lot of use by casual and experienced cyclists. The road surface is horrible, there is parallel parking on both sides of the street, and the road over the bridge always has holes in it. The bike lane seems to end somewhere around the Aquarium. As it continues past REI, the road narrows and there is increasing congestion at the 15th st intersection. Does anyone know if this important street will be improved any time soon for all vehicles concerned?

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