Santa Fe & Mineral Intersection Study
Public Meeting | Thursday, September 13 | 5:30 to 7 p.m.
WELCOME
Santa Fe & Mineral Intersection Study 01
Why is an intersection study necessary?The City of Littleton recognizes that the Santa Fe and Mineral intersection is challenging for motorists, cyclists, buses, and pedestrians. That is why the Department of Public Works is conducting a study of the intersection to develop potential design solutions to better serve the needs of the area both in the near and long term.
Increased DevelopmentThroughout the region, development has pushed more and more people to make trips through the corridor escalating congestion and safety issues the past few years.
ISSUE
ISSUE
ISSUE
Crash Related Safety ConcernsThere were 59 crashes related to this intersection in 2017 alone.Source: City of Littleton records
High-Cost of Traffic CongestionIn 2017, the impact of intersection congestion was $5.2 million in user costs.Source: INRIX, Santa Fe between Bowles Ave. and County Line Rd.
Santa Fe & Mineral Intersection Study 02
Project Location US 85 Corridor
Study Area
Future US 85 Planning & Environmental Linkages
Jackass Hill Road
UPRR / BNSF Freight Rail
RTD C/D Line
Aspen Grove Way
Future Development
Project Location
Santa Fe Drive /
RTD Mineral Light Rail Station
South Platte River
Mineral Avenue
RTD Park-n-Ride
Project Location
Completed US 85 Planning & Environmental Linkages
Santa Fe & Mineral Intersection Study 03
What are the existing conditions at the intersection?Santa Fe and Mineral is one of the worst functioning intersections in the City of Littleton. The area functions poorly throughout the day and experiences severe congestion in both the morning and evening peak hours.
Typical Peak Period SpeedsThe posted speed limit on Santa Fe through the Mineral intersection is 45 mph. But the average speed on Santa Fe through the intersection is only 36 mph for northbound and 38 mph for southbound. During peak periods, like morning and evening rush hour, average speeds typically slow significantly further.
The numbers above are based on an average of speeds from the past 365 days on Tuesdays, Wednesdays, and Thursdays.
Intersection Crashes by TypeThe number of rear end crashes near Santa Fe and Mineral from 2013 to 2017 — which are largely congestion-related — was at least six times more likely than all other crash types.
29MPH
AVERAGE SPEED ON A
NORMAL DAY
13MPH
AVERAGE SPEED ON A BAD DAY
8 A.M. NORTHBOUND
26MPH
AVERAGE SPEED ON A
NORMAL DAY
15MPH
AVERAGE SPEED ON A BAD DAY
5 P.M. SOUTHBOUND
Rear End72%
Angle10%
Side Swipe12%
Other6%
CRASHES BY TYPESanta Fe Drive at Mineral Avenue
(2013-2017)
Rear End Angle Side Swipe Other
72%Rear End
Other 6%
Side Swipe 12%
Angle 10%
Santa Fe & Mineral Intersection Study 04
Public Comments We asked you to share your thoughts on the Santa Fe and Mineral intersection. This is some of what we’ve heard so far:
Haven’t had a chance to tell us what you think? There is still time to take the survey at www.openlittleton.org
“I’ve seen multiple rear end crashes here due to everyone speeding
up and then hitting their brakes again when the
light turns red.”
“The biggest challenge is the bike lane that was carved out of westbound
Mineral which reduced the number of cars that could take a right hand turn onto Jackass Hill - Prince St.”
“I go well out of my way to get from my home to Aspen
Grove on a bike, because the thought
of riding on Mineral is inconceivable.”
“I travel through this intersection
about 5 times a week, mostly for shopping, access to light rail, or
to get to C470.”
“Occasionally I’ve caught myself delaying a trip past rush hour and then
never actually going out.”
“No reasonable alternatives.”
“You’re missing my tax dollars due to this intersection,
and the terrible light timing.”
“Too much traffic for the
limited space.”
Santa Fe & Mineral Intersection Study 05
Will the intersection issues get worse over time?In the future, traffic congestion is expected to worsen as development occurs both in the immediate vicinity of the intersection and throughout the region. That’s why the city is exploring short-term, implementable design solutions to better handle the existing and future traffic demands.
40,000
50,000
60,000
70,000
80,000
90,000
100,000
110,000
120,000
2015 2020 2025 2030 2035 2040 2045
MAI
NLI
NE
TRAF
FIC
VOLU
ME
(veh
/day
)
YEAR
Existing IntersectionCapacity
2017
Traffic forecasts can vary and become more uncertain the
farther into the future we look
The Santa Fe/Mineral intersection already
operates over capacity
Santa Fe & Mineral Intersection Study 06
Possible At-Grade SolutionsShort-Term Options
NO ACTION No construction required No right-of-way impacts Degrading traffic operations with growth Increased transit travel times with increased congestion Maintains existing safety deficiencies for all travel modes
Expanded Traditional Intersection
S Sa
nta
Fe D
r.
W Mineral Ave.
Wider footprint
Expanded Traditional Intersection
ALTERNATIVE 1
EVALUATION SUMMARY
Relatively Low-cost alternative
Minimal right-of-way impacts
Minimally improves intersection operations compared to No Action alternative
Increased transit travel times with increased congestion
Maintains existing safety deficiencies for all users, or worse due to wider intersection
Minimal change to signal timing.
Widen intersection with additional through and turn lanes for increased capacity.
S Sa
nta
Fe D
r.
W Mineral Ave.
Continuous Flow Intersection
Continuous Flow Intersection
ALTERNATIVE 2
EVALUATION SUMMARY
Reduces number and severity of left-turn conflicts
Improves traffic operations with increased capacity
Minimal impacts to adjacent property or RTD parking lot
Improves transit operations due to lower congestion
Requires multi-stage pedestrian crossings
Large amount of “throwaway” infrastructure if future grade separation occurs
Could be installed on Santa Fe only (as shown) or also along Mineral.
Left turns cross opposing traffic at new signals along the approach to the main intersection continuing through the main intersection with the opposing through movement.
S Sa
nta
Fe D
r.
W Mineral Ave.
No direct left turns at main intersection
All left turn traffic makes a U-turn at new signals. Seethe diagrams to the rightthat illustrate thesemovements.
Median U-Turn Intersection
WB Mineral Ave.
WB Mineral Ave.
EB Mineral Ave.
SB S
anta
Fe
Dr.
NB
San
ta F
e D
r.
WB Mineral Ave.
NB
San
ta F
e D
r.
SB S
anta
Fe
Dr.
NORTHBOUNDTO WESTBOUND
SOUTHBOUNDTO WESTBOUND
WESTBOUND TO SOUTHBOUND
EASTBOUND TO NORTHBOUND
Median U-Turn Intersection
ALTERNATIVE 4
EVALUATION SUMMARY
Relatively low cost for construction
Removes left-turn conflict points from main intersection
Installs wide median which may be useful for future grade separation
Requires longer travel distance for left-turning vehicles
Requires significant roadway widening
Minimally increases capacity at main intersection
Direct left turns to new signalized U-Turn intersection
Simplifying the signal timing at the main intersection, and coordinating with the new signals results in less congestion and lower overall travel times.
Simple construction at low cost
Improves transit operations due to lower congestion
Greatest improvement to traffic operations among at-grade alternatives
Reduces left-turn conflicts
Quadrant Intersection
S Sa
nta
Fe D
r.
W Mineral Ave.S Pl
atte
Riv
er P
kwy.
OPTION THROUGH DEVELOPMENTPotential future development can be accessed from the quadrant road.
New quadrant road
No left turns allowed at main intersection; simplifies operations
OPTION THROUGH RTD
WB Mineral Ave. EB Mineral Ave. EB Mineral Ave. WB Mineral Ave.
NB
San
ta F
e D
r.
SB S
anta
Fe
Dr.
NB
San
ta F
e D
r.
SB S
anta
Fe
Dr.
Intersection type to be determinded
NORTHBOUNDTO WESTBOUND
SOUTHBOUNDTO EASTBOUND
WESTBOUND TO SOUTHBOUND
EASTBOUND TO NORTHBOUND
Quadrant Intersection
ALTERNATIVE 3
EVALUATION SUMMARY
Requires longer travel distance for some left-turning vehicles especially when there is little to no congestion
Increases turning movement volumes at adjacent intersection
Requires right-of-way acquisition from RTD or development property
Left turns use the new quadrant road to make their turn movements (shown below).
Quadrant Intersection
S Sa
nta
Fe D
r.
W Mineral Ave.S Pl
atte
Riv
er P
kwy.
OPTION THROUGH DEVELOPMENTPotential future development can be accessed from the quadrant road.
New quadrant road
No left turns allowed at main intersection; simplifies operations
OPTION THROUGH RTD
WB Mineral Ave. EB Mineral Ave. EB Mineral Ave. WB Mineral Ave.
NB
San
ta F
e D
r.
SB S
anta
Fe
Dr.
NB
San
ta F
e D
r.
SB S
anta
Fe
Dr.
Intersection type to be determinded
NORTHBOUNDTO WESTBOUND
SOUTHBOUNDTO EASTBOUND
WESTBOUND TO SOUTHBOUND
EASTBOUND TO NORTHBOUND
Santa Fe & Mineral Intersection Study 07
Possible Grade-Separated SolutionsLong-Term Options
Diamond Interchange
S Sa
nta
Fe D
r.
W Mineral Ave.
Diamond Interchange
ALTERNATIVE 5
EVALUATION SUMMARY
Diverging Diamond Interchange
W Mineral Ave.
S Sa
nta
Fe D
r.W Mineral Ave.
Single Point Urban Interchange
MAINTAINS ONE SIGNAL ON MINERALSingle ramp signal simplifies operations
S Sa
nta
Fe D
r.
Diverging Diamond Interchange
ALTERNATIVE 6
EVALUATION SUMMARY
Displaced Left-Turn Interchange
W Mineral Ave.
S Sa
nta
Fe D
r.
W Mineral Ave.
Partial Cloverleaf Interchange
S Sa
nta
Fe D
r.
Displaced Left-Turn Interchange
ALTERNATIVE 7
EVALUATION SUMMARY
Significantly improves traffic/transit operations
Separates major traffic flow, improving safety for most users
Requires pedestrians/bicyclists to cross free-flow ramps
Significant right-of-way impacts to development property and RTD lot
Long, multi-phased construction period
One of the highest-cost alternatives Highest cost of all alternatives
Significantly improves traffic/transit operations
Separates major traffic flow, improving safety for most users
Requires pedestrians/bicyclists to cross free-flow ramps
Significant right-of-way impacts to development property and RTD lot
Long, multi-phased construction period
One of the highest-cost alternatives
Single Point Urban Interchange
ALTERNATIVE 8
EVALUATION SUMMARY
Partial Cloverleaf Interchange
ALTERNATIVE 9
EVALUATION SUMMARY
Greatest improvement to traffic/transit operations among all alternatives
Eliminates most severe left-turn conflicts with loop ramps
Requires pedestrians/bicyclists to cross free-flow ramps
Greatest right-of-way impacts of all alternatives
Long, multi-phased construction period
Separates major traffic flow, improving safety for most users
Significantly improves traffic/transit operations
Relatively minimal right-of-way requirements
Long, multi-phased construction period
Significantly higher cost than at-grade alternatives
Separates major traffic flow, improving safety for most users
Improves traffic/transit operations more than at-grade alternatives
Relatively minimal right-of-way requirements
Long, multi-phased construction period
Significantly higher cost than at-grade alternatives
Separates Santa Fe through traffic over Mineral.
Separates Santa Fe through traffic over Mineral.
Separates Santa Fe through traffic over Mineral.
Separates Santa Fe through traffic over Mineral.
Separates Santa Fe through traffic over Mineral.
Creates additional signal on Mineral
All traffic crosses over to opposite side of the road to better facilitate left turn movements.
Left turn traffic crosses over at additional signals to simplify signal phasing and improve operations.
Creates additional signal on Mineral.
Creates additional signal on Mineral.
Creates 3 additional signals on Mineral.
Santa Fe & Mineral Intersection Study 08
Schedule This study will determine a vision for the intersection. That vision will then be incorporated into the overall corridor Planning and Environmental Linkages (PEL) planned for 2019, and eventually the National Environmental Priority Act (NEPA) studies required for construction implementation.
July + Study Kickoff
August + Existing Conditions Analysis
+ Survey
September + Alternatives Evaluation
+ Public Open House #1
November + Stakeholder Input
+ Feasibility Evaluation
+ Cost Estimates
October + Detailed Evaluation of Alternatives
+ Conceptual Design
SANTA FE & MINERAL INTERSECTION STUDY
2018: Planning & Feasibility Study
+ Short-term improvements + Identify long-term vision for this
intersection
US 85 PEL – C-470 TO I-25
2019: Planning & Environmental Linkages
+ Identify a long-term vision for the entire corridor + Identify additional early action projects at
specific locations
US 85 NEPA PROCESS
Post-2020: Environmental + Identify funding for long-term projects
+ Perform environmental analysis to gain approval for projects
+ Implementation plan for long-term vision
US 85 PROJECT IMPLEMENTATION
Post-2020: Construction
+ Identify priority projects + Perform design + Identify funding sources
December + Selection of Short Term and Long Term Alternatives
+ Public Open House #2
+ Final Report
Santa Fe & Mineral Intersection Study
THANK YOUFOR JOINING US
We understand congestion is tough on our neighbors and drivers.Our top priority is to improve safety and minimize impacts, while keeping you informed.
Learn More Online
www.littletongov.org/santafe-mineralProvide Feedback
www.openlittleton.org
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