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Cityscape: The Greening of the Drive

The urban forestry experiment on Lake Shore Drive is working, at hardly any cost or inconvenience to anyone. The mayor's school plans should turn out so well.

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The appearance last year of city crews planting trees in the middle of the north end of Lake Shore Drive inspired some snickering among commuters and newspaper columnists. The trees were, after all, the most visible symbol of Mayor Daley's enthusiasm for planting--few things seem to light the mayor's fire quite like urban forestry. Last winter the drive's speed limit was lowered to 40 miles per hour in the name of preserving the trees from road salt, and motorists ticketed for breaking the limit probably harbored dark thoughts about chain saws and termites. But the trees are here to stay; this fall they spread to part of South Lake Shore Drive. The winter speed limit may be too. The fact is the effort to beautify the drive is working, and it's bringing other benefits, at hardly any cost or inconvenience to anyone. The mayor's schools plan should work so well.

The drive planting effort was born in tragedy: a couple of nasty accidents in recent years, in which motorists flew across the median and people died, moved the city and state transportation departments to install thick concrete "Jersey blocks" to prevent more. But Friends of the Parks threatened to sue the city and the Park District for failing to explore less ugly options, and the group had won a similar lawsuit in the past.

At the same time Mayor Daley's "Green Streets" program was on the lookout for places to plant trees. The upshot was a joint city-Park District project in which about 1,000 trees were planted from Oak Street to Hollywood, along with hedges and perennial flowers; a sprinkler system was laid atop the soil beneath a layer of mulch. Experts from the Morton Arboretum served as advisers.

Of necessity the project was an experiment, says Green Streets director Karen Nowacki. "We couldn't find a similar thing in any of the large cities of the midwest." Nearly all of the urban waterfront parkways in this country, though perhaps originally planned with landscaping, are now treated more or less as expressways. Planners have long assumed that the exhaust, heat, salt, vibration, and other hazards of urban freeways would kill off anything planted in the middle of them.

Hedging their bets, the city and Park District planted a wide variety of trees: hawthorn, crab apple, ash, red oak, hackberry, honey locust, ginkgoes, and Kentucky coffee trees (evergreens can't stand the winter salt spray). It's too early to tell which species will do best in the long term, but Nowacki says 85 percent of the plants are still alive. "We're very pleased." Around $1.5 million has been spent so far, most on the initial planting.

None of the species grow to be really huge, but even if they did we wouldn't have great limbs looming over and occasionally falling onto the drive. Trees must be able to send their roots ever farther afield as they grow, and the drive trees are in what's essentially a very long planter--only a few feet wide and 48 inches deep. Since the roots of most deciduous trees spread mainly out, not down, 48 inches of soil is enough to keep them healthy. But they don't have enough room to really spread roots and get large; we're not likely to see any trees more than 25 feet tall in the median.

Falling leaves are not a problem. "These are mostly small-leafed trees," says Nowacki, "and Streets and Sanitation sweeps twice a week." However, now that the leaves have turned and dropped, the median has a kind of bare look. A private contractor is responsible for periodically refreshing the mulch, as well as monitoring the sprinkling system, pruning, and doing the other chores that keep trees healthy amid the stresses of an urban environment.

Erma Tranter of Friends of the Parks is happy. "We say it should continue and be expanded south as a good solution to a safety problem. Trees on a roadway provide wind barriers, cooling in summer, and help absorb some of the exhaust pollution. And aesthetically it's wonderful." Nowacki echoes her. "We've received a number of compliments."

At the suggestion of the Morton Arboretum, the city and state transportation departments gave their blessing to lowering the speed limit by five miles per hour last winter. According to Nowacki, weekly bud and twig tests showed that salt spray on the trees was "significantly less" than at the old speed limit, though a three-foot fabric fence helped. The various agencies are now discussing whether to make the experiment permanent.

The speed limit may be more an emotional issue for motorists than a real inconvenience: traveling the six miles from Hollywood to Oak Street takes about eight minutes at 45 miles per hour and about nine minutes at 40 miles per hour. Besides, the speed limit isn't really relevant at the height of rush hour, and in winter road conditions often force drivers to go less than 40.

The planting on South Lake Shore Drive is now confined to the stretch from 31st to 47th streets. Farther south there's no median to plant in, and farther north the drive is under temporary control of the McCormick Place-Navy Pier redevelopment commission, though the McCormick expansion plans could make the drive's green median virtually continuous between Hollywood and 47th Street.

Extending the median farther south is dicier, because it would mean reconfiguring the roadway. "We are currently studying what can be done there, taking into account lane widths and traffic patterns and so forth," Nowacki says. "We should have an answer in a couple of months." Friends of the Parks has written the state Department of Transportation asking that funds be made available, but the state has not yet responded.

So far none of the ongoing spasm of freeway construction in and around Chicago ("The city that detours") has included any tree-lined medians. A call to the state Department of Transportation to ask about that yielded a couple of puzzled silences and a promise to have someone get back to me.

But it's easy to guess what the response would be. Much of the median of the Kennedy, Dan Ryan, and Eisenhower expressways is taken up by el tracks, and the higher speeds, heavier traffic and pollution, and greater noise and vibration on the expressways might well kill anything woody planted in them. Pending the creation of some supertough hawthorn, ash, or crab apple trees Lake Shore Drive seems certain to remain the greenest and prettiest freeway in these parts.

Art accompanying story in printed newspaper (not available in this archive): photo/Mike Tappin.

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