Each of the build alternatives include improvements along both directions of I-25 from the Jefferson Street interchange to the Alameda interchange to address mainline capacity needs and to accommodate entrance and exit ramp modifications along I-25.  The general improvements to I-25 that are expected to result from the I-25/Paseo del Norte project are listed below.  Some variation in ramp layouts occurs by alternative north of the San Antonio Drive Interchange.  Click on this link for an illustration of Alternative 7, or click on this link for an illustration of Alternative 16.  

Alternative 7

Alternative 7 includes improvements to the I-25 mainline, ramp roadways, and frontage roads beginning at the Jefferson Street Interchange and extending north to the Alameda Boulevard Interchange.  The major design features for the I-25 corridor are listed below.

Northbound I-25

• Add a fourth northbound travel lane from Jefferson Street to the Alameda Boulevard exit ramp.
• Add a northbound auxiliary lane (ramp-to-ramp lane) from the Jefferson Street entrance ramp to the San Antonio Drive exit ramp and from the San Mateo Boulevard/Osuna Road entrance ramp to the Paseo del Norte northbound-to-westbound directional ramp.
• Add a new northbound entrance ramp from San Mateo Boulevard/Osuna Road.  This ramp would be braided (one ramp passing over another) with the existing exit ramp to San Antonio Drive. 
• Eliminate the existing northbound entrance ramp from San Antonio Drive.
• Add an exit ramp between northbound I-25 and the frontage road north of San Antonio Drive; this ramp functions as the exit ramp to eastbound Paseo del Norte and other local destinations.
• Relocate the northbound entrance ramp from Paseo del Norte and the exit ramp to Alameda Boulevard.  The Alameda exit ramp is relocated near Paseo del Norte and the Paseo del Norte entrance ramp is near Alameda Boulevard.  This configuration moves lane changing maneuvers between vehicles entering and exiting the freeway mainline onto the frontage road where speeds and traffic volumes are lower.
• Add a third lane on the segments of the northbound frontage road where access to and from I-25 is modified.
• Provide shoulders on both sides of the freeway mainline consistent with current design standards.  Inside and outside shoulders would be a minimum of 10-feet wide.

Southbound I-25

• Relocate the existing Alameda exit ramp several hundred feet further north.  Traffic accessing Alameda Boulevard, Paseo del Norte and San Antonio Drive/Ellison Street from southbound I-25 would use this ramp.
• Eliminate the southbound exit ramp to Paseo del Norte. 
• Add a fourth travel lane in the southbound direction from Paseo del Norte through the Jefferson Street overpass.
• Add a southbound auxiliary lane (ramp-to-ramp lane) from the new entrance ramp near San Francisco Road to the San Mateo Boulevard/Osuna Road exit ramp and from the San Mateo Boulevard/Osuna Road entrance ramp to the Jefferson Street exit ramp.
• Eliminate the existing southbound exit ramp to San Antonio Drive.
• Add an entrance ramp between the southbound frontage road and the I-25 mainline south of San Francisco Road; this ramp functions as a second Paseo del Norte entrance ramp.
• Eliminate the existing southbound-to-eastbound loop exit ramp at San Mateo Boulevard/Osuna Road.  This ramp would be replaced by a new exit ramp to San Mateo Boulevard/Osuna Road. 
• Braid the southbound entrance ramp from San Antonio Drive/Ellison Street with the new San Mateo Boulevard/Osuna Road exit ramp.
• Provide shoulders on both sides of the freeway mainline consistent with current design standards.  Inside and outside shoulders would be a minimum of 10-feet wide.

Alternative 16

Alternative 16 generally includes the same improvements to the I-25 mainline, ramp roadways, and frontage roads.  As with Alternative 7, the changes to I-25 begin at the Jefferson Street Interchange and extend north to the Alameda Boulevard Interchange.  The differences between Alternative 7 and Alternative 16 are described below.

Northbound I-25

• A ramp between the northbound frontage road and the freeway mainline is added just south of Paseo del Norte.  This ramp provides access to northbound I-25 for traffic entering the frontage road at San Antonio Drive as well as from access points along the frontage road north of San Antonio Drive.
• The northbound exit ramp at Alameda Boulevard is maintained in its current location.  In Alternative 7, this ramp was relocated south to a point just north of Paseo del Norte.
• The northbound entrance ramp from Paseo del Norte to I-25 is eliminated.  With Alternative 16, this traffic is routed through the existing on-ramp at Alameda Boulevard via either San Pedro Drive, Louisiana Boulevard, or other north-south streets that connect to Alameda Boulevard east of I-25.

Southbound I-25

• A southbound I-25 to westbound Paseo del Norte free-flow ramp is provided; however, access to east Paseo del Norte and the Domingo Baca Arterial occurs at the Alameda Boulevard southbound exit ramp.
• The on-ramp between the southbound frontage road and the I-25 mainline south of San Francisco Road is eliminated.  The access provided by this ramp is now served by the westbound to southbound flyover ramp, and by the San Antonio Drive and San Mateo Boulevard/Osuna Road entrance ramps. 
• A southbound auxiliary lane (ramp-to-ramp lane) is provided from the Paseo del Norte directional ramp to the San Mateo Boulevard/Osuna Road exit ramp.