A Routing Probl… err, Challenge

Wheel full 70pxMy great friend and true Southern gentleman Kevin Slark commented on my latest routing post [linkie] over on my facebook page [linkie] to let me know that crossing the Mississippi River from Louisiana to Mississippi at Vicksburg might not be an option.

KS Facebook comment 01

Wheel full 70pxReal Life, as it tends to, intervened and I really didn’t have a chance to get back to this issue until today.

Wheel full 70pxHere’s what Kevin is talking about.  The 86 year old bridge that carried US highway 80 across the Mississippi River just west of Vicksburg

Old US 80 Bridge at Vicksburg 800px

Image credit: Wikipedia

is currently closed to all traffic, vehicular, bicycle and pedestrian, except for a couple of days of the year when it is opened for special events, such as a community bike ride this year on October 1st [linkie].  The bridge carries a rail line and has very narrow vehicle lanes

Old US 80 Bridge Deck 800px

Image credit: Vicksburg Post

and the railroad operating the line has repeatedly objected to reopening the bridge to regular bicycle and pedestrian use despite efforts by cycling and walking enthusiasts and advocates to have this done [linkie].  Unless I can get my crossing declared a special event, it does not look good for me to be able to use the bridge towards the end of August in the fourth week of my ride.

Wheel full 70pxThe old US 80 bridge was replaced as the primary Vicksburg area Mississippi River crossing in 1973 by the Interstate 20 bridge

I-20 Bridge at Vicksburg 800px

Image credit: Wikimedia

which is now, interestingly enough, exactly half the age of the other structure.  The two run parallel to each other,

Mississippi River Bridges at Vicksburg 800px

Image credit: Vicksburg Post

and the pier spacing is exactly the same to facilitate the passage of barge traffic up and down the Mississippi.

Wheel full 70pxBut the bottom line is that the State of Mississippi does not allow bicycle traffic on any of its Interstate Highways, period, and my use of the I-20 bridge is thus not possible.  I called the Mississippi State Bicycle (& Pedestrian) Coordinator [linkie] today and confirmed that there was no exception for this particular crossing.  She said that there was not, but encouraged me to contact various groups concerning my desire to use the old US 80 bridge.  I will follow up on that tomorrow but, as noted, I am not hopeful.

US 80 300px

Wheel full 70pxKevin apparently anticipated this result, as he recommended an alternative crossing.

KS Facebook comment 02

Crossing at Natchez would not involve a huge modification to the route I have planned.  It replaces a 94 mile/151 kilometer stretch from MP 997 to MP 1091 with an 85.4 mile/~137 kilometer alternate.  The red line is the current route and blue is the alternate.

Current Route Natchez-Vicksburg

The alternate is surprisingly (to me, anyway) about ten percent shorter, even though it doesn’t look it.  Here’s the above map reversed, with the alternate in red and the current route in blue.

Alternate Route Natchez-Vicksburg

Most of the alternate route’s mileage is on the Natchez Trace [linkie], which is an amazing low speed (45 miles/~70 kilometers per hour) scenic national parkway in a beautiful right-of-way.  Heather and I have biked this stretch in the late 1990s on our Burley Rock’n’Roll tandem [linkie].  I seriously considered incorporating it into the original route for this trip.

Wheel full 70pxThe reason I ultimately didn’t can be seen on the above map.  Note that the terrain on the Louisiana (left) side of the Mississippi is smooth.  East of the river, though, the landform changes pretty radically into low but steep hills cross-cut by deeply incised streams.  Here’s an elevation chart of the current stretch

Current Route Elevations Natchez-Vicksburg

and of the alternate done at the same vertical scale.

Alternate Route Elevations Natchez-Vicksburg

Here’s the two superimposed.  Click on any of the three charts to embiggen.

Comparison Elevations Current Alternate Natchez-Vicksburg 800px

Wheel full 70pxSo that’s a little sooner than I’d planned to start doing hills.  But I’ll have just about 1,000 miles under my belt before I get to them, so they shouldn’t be too bad.  Hey- maybe I can still become an event and cross the old US 80 bridge.  But if not, well… I have a plan!

David Edgren